The Expert Expert

Moonwalking with Einstein: The Art and Science of Remembering Everything - Joshua Foer 2012

The Expert Expert

Though it’s best not to be born a chicken at all, it is especially bad luck to be born a cockerel.

From the perspective of the poultry farmer, male chickens are useless. They can’t lay eggs, their meat is stringy, and they’re ornery to the hens that do all the hard work of putting food on our tables. Commercial hatcheries tend to treat male chicks like fabric cutoffs or scrap metal: the wasteful but necessary by-product of an industrial process. The sooner they can be disposed of—often they’re ground into animal feed—the better. But a costly problem has vexed egg farmers for millennia: It’s virtually impossible to tell the difference between male and female chickens until they’re four to six weeks old, when they begin to grow distinctive feathers and secondary sex characteristics like the rooster’s comb. Until then, they’re all just indistinguishable fluff balls that have to be housed and fed—at considerable expense.

Somehow it took until the 1920s before anyone figured out a solution to this costly dilemma. The momentous discovery was made by a group of Japanese veterinary scientists, who realized that just inside the chick’s rear end there is a constellation of folds, marks, spots, and bumps that to the untrained eye appear arbitrary, but when properly read, can divulge the sex of a day-old bird. When this discovery was unveiled at the 1927 World Poultry Congress in Ottawa, it revolutionized the global hatchery industry and eventually lowered the price of eggs worldwide. The professional chicken sexer, equipped with a skill that took years to master, became one of the most valuable workers in agriculture. The best of the best were graduates of the two-year Zen-Nippon Chick Sexing School, whose standards were so rigorous that only 5 to 10 percent of students received accreditation. But those who did graduate earned as much as five hundred dollars a day and were shuttled around the world from hatchery to hatchery like top-flight business consultants. A diaspora of Japanese chicken sexers spilled across the globe.

Chicken sexing is a delicate art, requiring Zen-like concentration and a brain surgeon’s dexterity. The bird is cradled in the left hand and given a gentle squeeze that causes it to evacuate its intestines (too tight and the intestines will turn inside out, killing the bird and rendering its gender irrelevant). With his thumb and forefinger, the sexer flips the bird over and parts a small flap on its hindquarters to expose the cloaca, a tiny vent where both the genitals and anus are situated, and peers deep inside. To do this properly, his fingernails have to be precisely trimmed. In the simple cases—the ones that the sexer can actually explain—he’s looking for a barely perceptible protuberance called the “bead,” about the size of a pinhead. If the bead is convex, the bird is a boy, and gets thrown to the left; concave or flat and it’s a girl, sent down a chute to the right. Those cases are easy enough. In fact, a study has shown that amateurs can be taught to identify the bead with only a few minutes of training. But in roughly 80 percent of the chicks, the bead is not obvious and there is no single distinguishing trait the sexer can point to.

By some estimates there are as many as a thousand different vent configurations that a sexer has to learn to become competent. The job is made even more difficult by the fact that the sexer has to diagnose the bird with just a glance. There is no time for conscious reasoning. If he hesitates for even a couple seconds, his grip on the bird can cause a pullet’s vent to swell to look unquestionably like a cockerel’s. Mistakes are costly. In the 1960s, one hatchery paid its sexers a penny for each correctly sexed chick and deducted 35 cents for each one they got wrong. The best in the business can sex 1,200 chicks an hour with 98 to 99 percent accuracy. In Japan, a few superheroes of the industry have learned how to double clutch the chicks and sex them two at a time, at the rate of 1,700 per hour.

What makes chicken sexing such a captivating subject—the reason that academic philosophers and cognitive psychologists have authored dissertations about it, and the reason that my own research into memory had brought me to this arcane skill—is that even the best professional sexers can’t describe how they determine gender in the toughest, most ambiguous cases. Their art is inexplicable. They say that within three seconds they just “know” whether a bird is a boy or a girl, but they can’t say how they know. Even when carefully cross-examined by researchers, they can’t give reasons why one bird is a male and another is female. What they have, they say, is intuition. In some fundamental sense, the expert chicken sexer perceives the world—at least the world of chicken privates—in a way that is completely different from you or me. When they look at a chick’s bottom, they see things that a normal person simply does not see. What does chicken sexing have to do with my memory? Everything.


I decided it would be a good idea to dive (bellyflop, really) into the scientific literature. I was looking for some hard evidence that our memories might really be improvable in the dramatic way that Buzan and the mental athletes had promised. I didn’t have to search very hard. As I was combing the scientific literature, one name kept popping up in my research about memory improvement: K. Anders Ericsson. He was a psychology professor at Florida State University and the author of an article titled “Exceptional Memorizers: Made, Not Born.”

Before Tony Buzan mass-marketed the idea of “using your perfect memory,” Ericsson was laying the scientific groundwork for what’s known as “Skilled Memory Theory,” which explains how and why our memory is improvable. In 1981, he and fellow psychologist Bill Chase conducted a now-classic experiment on a Carnegie Mellon undergraduate, who has been immortalized in the literature by his initials, SF. Chase and Ericsson paid SF to spend several hours a week in their lab taking a simple memory test over and over and over again. It was similar to the test that Luria had given to S when he first walked into his office. SF sat in a chair and tried to remember as many numbers as possible as they were read off at the rate of one per second. At the outset, he could only hold about seven digits in his head at a time. By the time the experiment wrapped up—two years and 250 mind-numbing hours later—SF had expanded his ability to remember numbers by a factor of ten. The experiment shattered the old notions that our memory capacities are fixed. How SF did it, Ericsson believes, holds a key to understanding the basic cognitive processes underlying all forms of expertise—from mental athlete memorizers to chess grand masters to chicken sexers.

Everyone has a great memory for something. We’ve already seen the mnemonic gifts of London cabbies, and the scientific literature is filled with papers about the “superior memories” of waiters, the vast capacities of actors to remember lines, and the memory skills possessed by experts in a wide variety of other fields. Researchers have studied the exceptional memories of doctors, baseball fans, violinists, soccer players, snooker players, ballet dancers, abacus wranglers, crossword puzzlers, and volleyball defenders. Pick any human endeavor in which people excel, and I’ll give you even odds that some psychologist somewhere has written a paper about the exceptional memories possessed by experts in that field.

Why is it that veteran waiters don’t have to write down orders? Why are the best violinists in the world so good at memorizing new musical scores? How come, as one study proved, elite soccer players can glance at a soccer match on TV and reconstruct almost exactly what was happening in the game? One possible explanation might be that people with good memories for dinner orders get channeled into the food-service industry, or that the soccer players with the best memory for arrangements of players have a knack for clawing their way up to the premier league, or that people with a great eye for chicken ass naturally gravitate to the Zen-Nippon Chick Sexing School. But that seems unlikely. It makes much more sense to believe the causality works in the opposite direction. There is something about mastering a specific field that breeds a better memory for the details of that field. But what is that something? And can that something somehow be generalized, so that anyone can acquire it?

The Human Performance Lab, which Ericsson runs with a group of other FSU researchers, is where experts come to have their memories—and much else—tested. Ericsson is probably the world’s leading expert on experts. Indeed, he has achieved a degree of popular fame in recent years thanks to his research showing that experts tend to require at least ten thousand hours of training to achieve their world-class status. When I called him up and told him that I had been thinking about trying to train my own memory, he wanted to know whether I had started yet. I said I hadn’t really begun. He was thrilled; he told me he almost never gets the chance to study a novice in the process of becoming an expert. If I was serious, he said, he wanted to make me his research subject. He invited me down to Florida for a couple days to take a few tests. He wanted to get some baseline measurements of my memory before I started trying to improve it.

The Human Performance Lab occupies a plush office complex on the outskirts of Tallahassee. The bookshelves that line the walls overflow with an eclectic catalog of titles that have been relevant to Ericsson’s research: The Musical Temperament, Surgery of the Foot, How to Be a Star at Work, Secrets of Modern Chess Strategy, Lore of Running, The Specialist Chick Sexer.

David Rodrick, a young research associate in the lab, gleefully described the place as “our toy palace.” When I arrived a couple weeks after my initial phone call with Ericsson, there was a floor-to-ceiling nine-by-fourteen-foot screen set up in the middle of one of the rooms displaying life-size video footage of a traffic stop. It was shot from the perspective of a police officer walking up to a stopped car.

For the previous few weeks, Ericsson and his colleagues had been bringing members of the Tallahassee SWAT team and recent graduates of the police academy into his lab and placing them in front of the big screen with a Beretta handgun loaded with blanks holstered to their belt. They bombarded the officers with one hair-raising scenario after another and watched how they responded. In one scenario, the officer saw a man walk toward the front door of a school with a suspicious bulge that looked like a bomb strapped to his chest. The researchers wanted to know how officers with different levels of experience would react.

The results were striking. Experienced SWAT officers immediately pulled their guns and yelled repeatedly for the suspect to stop. When he didn’t, they almost always shot him before he made it into the school. But recent graduates of the academy were more likely to let the man with the bomb stroll right up the steps and into the building. They simply lacked the experience to diagnose the situation and react properly. At least that would be the superficial explanation. But what exactly does experience mean? What exactly did the more senior officers see that the younger recruits didn’t? What were they doing with their eyes, what was going through their minds, how were they processing the situation differently? What were they pulling from their memories? Like the professional chicken sexers, the senior SWAT officers had a skill that was difficult to put into words. Ericsson’s research program can be summarized as an attempt to isolate the thing we call expertise, so that he can dissect it and identify its cognitive basis.

In order to do that, Ericsson and his colleagues asked the officers to talk aloud about what was going through their minds as the scenario unfolded. What Ericsson expected to learn from these accounts was the same thing he’s found in every other field of expertise that he’s studied: Experts see the world differently. They notice things that nonexperts don’t see. They home in on the information that matters most, and have an almost automatic sense of what to do with it. And most important, experts process the enormous amounts of information flowing through their senses in more sophisticated ways. They can overcome one of the brain’s most fundamental constraints: the magical number seven.


In 1956, a Harvard psychologist named George Miller published what would become a classic paper in the history of memory research. It began with a memorable introduction:

My problem is that I have been persecuted by an integer. For seven years this number has followed me around, has intruded in my most private data, and has assaulted me from the pages of our most public journals. This number assumes a variety of disguises, being sometimes a little larger and sometimes a little smaller than usual, but never changing so much as to be unrecognizable. The persistence with which this number plagues me is far more than a random accident. There is, to quote a famous senator, a design behind it, some pattern governing its appearances. Either there really is something unusual about the number or else I am suffering from delusions of persecution.

In fact, we are all persecuted by the integer Miller was referring to. His paper was titled “The Magical Number Seven, Plus or Minus Two: Some Limits on Our Capacity for Processing Information.” Miller had discovered that our ability to process information and make decisions in the world is limited by a fundamental constraint: We can only think about roughly seven things at a time.

When a new thought or perception enters our head, it doesn’t immediately get stashed away in long-term memory. Rather, it exists in a temporary limbo, in what’s known as working memory, a collection of brain systems that hold on to whatever is rattling around in our consciousness at the present moment.

Without looking back and rereading it, try to repeat the first three words of this sentence to yourself.

Without looking back

Easy enough.

Now, without looking back, try to repeat the first three words of the sentence before that. If you find that quite a bit harder, it’s because that sentence has already been dropped by your working memory.

Our working memories serve a critical role as a filter between our perception of the world and our long-term memory of it. If every sensation or thought was immediately filed away in the enormous database that is our long-term memory, we’d be drowning, like S and Funes, in irrelevant information. Most of the things that pass through our brain don’t need to be remembered any longer than the moment or two we spend perceiving them and, if necessary, reacting to them. In fact, dividing memory between short-term and long-term stores is such a savvy way of managing information that most computers are built around the same model. They have long-term memories in the form of hard drives as well as a working memory cache in the CPU that stores whatever the processor is computing at the moment.

Like a computer, our ability to operate in the world, is limited by the amount of information we can juggle at one time. Unless we repeat things over and over, they tend to slip from our grasp. Everyone knows our working memory stinks. Miller’s paper explained that it stinks within very specific parameters. Some people can hold as few as five things in their head at any given time, a few people can hold as many as nine, but the “magical number seven” seems to be the universal carrying capacity of our short-term working memory. To make matters worse, those seven things only stick around for a few seconds, and often not at all if we’re distracted. This fundamental limitation, which we all share, is what makes us find the feats of memory gurus so amazing.

My own memory test did not occur in front of the Human Performance Lab’s floor-to-ceiling projection screen. There were no guns holstered to my belt, no eye-tracking devices attached to my head. My humble contribution to human knowledge was extracted in Room 218 of the FSU psychology department, a small windowless office with a stained carpet and old IQ tests strewn across the floor. Ungenerously, it might be described as a storage closet.

The man administering my tests was a third-year PhD student in Ericsson’s lab named Tres Roring. Though his flip-flops and blond surfer mop might not suggest it, Tres grew up in a small town in southern Oklahoma, where his father is an oil man. At age sixteen, he was the Oklahoma State Junior Chess Champion. His full name is Roy Roring III—hence “Tres.”

Tres and I spent three full days in Room 218 taking memory test after memory test—me wearing a clunky microphone headset attached to an old tape recorder, Tres sitting behind me, legs crossed, with a stopwatch in his lap, taking notes.

There were tests of my memory for numbers (forward and backward), tests of my memory for words, tests of my memory for people’s faces, and tests of all sorts of things that seemed unlikely to have anything to do with my memory—like whether I could visualize rotating cubes in my mind’s eye, and whether I knew the definitions of “jocose,” “lissome,” and “querulous.” Another multiple-choice exam called the Multidimensional Aptitude Battery Information Test gauged my Trivial Pursuit skills with questions like:

When did Confucius live?

a. 1650 A.D.

b. 1200 A.D.

c. 500 A.D.

d. 500 B.C.

e. 40 B.C.


In a gasoline engine, the main purpose of the carburetor is to

a. mix gasoline and air

b. keep the battery charged

c. ignite the fuel

d. contain the pistons

e. pump the fuel into the engine

Many of the tests Tres administered were lifted directly from U.S. Memory Championship events, like the fifteen-minute poem, names and faces, random words, speed numbers, and speed cards. He wanted to see how I’d do on them before I’d ever tried to improve my memory. He also wanted to test me on a few of the events that are only used in international memory competitions, like binary digits, historical dates, and spoken numbers. By the end of my three days in Tallahassee, Tres had collected seven hours of audiotaped data for Ericsson and his grad students to analyze later. Lucky them.

And then there were the extensive interviews conducted by another graduate student, Katy Nandagopal. Do you think you have a good natural memory? (Pretty good, but nothing special.) Did you ever play memory games growing up? (Not that I can think of.) Board games? (Only with my grandmother.) Do you enjoy riddles? (Who doesn’t?) Can you solve a Rubik’s cube? (No.) Do you sing? (Only in the shower.) Dance? (Ditto.) Do you work out? (Sore subject.) Do you use workout tapes? (You need to know that?) Do you have electrical wiring expertise? (Really?)

For someone who wants to know what’s being done to him so that he might someday tell other people about it, being the subject of a scientific study can be exceedingly trying.

“Why exactly are we doing this?” I’d ask Tres.

“I’d rather not tell you everything right now.” (If there was something I was going to be tested on later—and as it turned out, there was—he didn’t want me to know.)

“How did I do on that last test?”

“We’ll let you know when this is all done.”

“Can you at least tell me about your hypothesis?”

“Not now.”

“What’s my IQ?”

“I don’t know.”

“High, though?”

The mind-numbing memory exam that SF, the Carnegie Mellon undergraduate, took over and over again for 250 hours for two years is known as the digit span test. It is a standard measure of a person’s working-memory capacity for numbers. Most people who are given the test are like SF when he started: They’re only able to remember seven plus-or-minus two digits. Most people remember those seven plus-or-minus two numbers by repeating them over and over again to themselves in the “phonological loop,” which is just a fancy name for the little voice that we can hear inside our head when we talk to ourselves. The phonological loop acts as an echo, producing a short-term memory buffer that can store sounds just a couple seconds, if we’re not rehearsing them. When he began participating in Chase and Ericsson’s experiment, SF also used his phonological loop to store information. And for a long time his scores on the test didn’t improve. But then something happened. After hours of testing, SF’s scores started inching up. One day he remembered ten digits. The next day it was eleven. The number of digits he could recall kept rising steadily. He had made a discovery: Even if his short-term memory was limited, he’d figured out a way to store information directly in long-term memory. It involved a technique called chunking.

Chunking is a way to decrease the number of items you have to remember by increasing the size of each item. Chunking is the reason that phone numbers are broken into two parts plus an area code and that credit card numbers are split into groups of four. And chunking is extremely relevant to the question of why experts so often have such exceptional memories.

The classic explanation of chunking involves language. If you were asked to memorize the twenty-two letters HEADSHOULDERS-KNEESTOES, and you didn’t notice what they spelled, you’d almost certainly have a tough time with it. But break up those twenty-two letters into four chunks—HEAD, SHOULDERS, KNEES, and TOES—and the task becomes a whole lot easier. And if you happen to know the full nursery rhyme, the line “Head, shoulders, knees, and toes” can effectively be treated like one single chunk. The same can be done with numbers. The twelve-digit numerical string 120741091101 is pretty hard to remember. Break it into four chunks—120, 741, 091, 101—and it becomes a little easier. Turn it into two chunks, 12/07/41 and 09/11/01, and they’re almost impossible to forget. You could even turn those dates into a single chunk of information by remembering it as “the two big surprise attacks on American soil.”

Notice that the process of chunking takes seemingly meaningless information and reinterprets it in light of information that is already stored away somewhere in our long-term memory. If you didn’t know the dates of Pearl Harbor or September 11, you’d never be able to chunk that twelve-digit numerical string. If you spoke Swahili and not English, the nursery rhyme would remain a jumble of letters. In other words, when it comes to chunking—and to our memory more broadly—what we already know determines what we’re able to learn.

Though he’d never been properly taught the technique of chunking, SF figured it out on his own. An avid runner, he began thinking of the strings of random numbers as running times. For example 3,492 was turned into “3 minutes and 49 point 2 seconds, near world-record mile time.” And 4,131 became “4 minutes, 13 point 1 seconds, a mile time.” SF didn’t know anything about the random numbers he had to memorize, but he did know about running. He discovered that he could take meaningless bits of information, run them through a filter that applied meaning to them, and make that information much stickier. He had taken his past experiences and used them to shape how he perceived the present. He was using associations in his long-term memory to see the numbers differently.

This, of course, is what all experts do: They use their memories to see the world differently. Over many years, they build up a bank of experience that shapes how they perceive new information. The experienced SWAT officer doesn’t just see a man walking up the front steps of the school; he sees a nervous twitch in the man’s arm that calls up associations with dozens of other nervous twitches he’s seen in his years of policing. He sees the suspect in the context of every other suspicious person he’s ever come across. He perceives the current encounter in light of past encounters like it.

When a graduate of the Zen-Nippon Chick Sexing School looks at a chick’s bottom, finely honed perceptual skills allow the sexer to quickly and automatically gather up a stock of information embedded in the chick’s anatomy, and before a conscious thought can even enter his or her head, the sexer knows whether the chick is a boy or a girl. But as with the senior SWAT officer, that seemingly automatic knowledge is hard earned. It is said that a student of sexing must work through at least 250,000 chicks before attaining any degree of proficiency. Even if the sexer calls it “intuition,” it’s been shaped by years of experience. It is the vast memory bank of chick bottoms that allows him or her to recognize patterns in the vents glanced at so quickly. In most cases, the skill is not the result of conscious reasoning, but pattern recognition. It is a feat of perception and memory, not analysis.

The classic example of how memories shape the perception of experts comes from what would seem to be the least intuitive of fields: chess. Practically since the origins of the modern game in the fifteenth century, chess has been regarded as the ultimate test of cognitive ability. In the 1920s, a group of Russian scientists set out to quantify the intellectual advantages of eight of the world’s best chess players by giving them a battery of basic cognitive and perceptual tests. To their surprise, the researchers found that the grand masters didn’t perform significantly better than average on any of their tests. The greatest chess players in the world didn’t seem to possess a single major cognitive advantage.

But if chess masters aren’t, as a whole, smarter than lesser chess players, then what are they? In the 1940s, a Dutch psychologist and chess aficionado named Adriaan de Groot asked what seemed like a simple question: What separates merely good chess players from those who are world-class? Did the best-class players see more moves ahead? Did they ponder more possible moves? Did they have better tools for analyzing those moves? Did they simply have a better intuitive grasp of the dynamics of the game?

One of the reasons chess is such a satisfying game to play and to study is that your average chess buff can be utterly befuddled by a master’s move. Often the best move seems entirely counterintuitive. Realizing this, De Groot pored through old games between chess masters and selected a handful of board positions where there was definitely one correct, but not obvious, move to be made. He then presented the boards to a group of international chess masters and top club players. He asked them to think aloud while they brooded over the proper move.

What De Groot uncovered was an even bigger surprise than what his Russian predecessors had found. For the most part, the chess experts didn’t look more moves ahead, at least not at first. They didn’t even consider more possible moves. Rather, they behaved in a manner surprisingly similar to the chicken sexers: They tended to see the right moves, and they tended to see them almost right away.

It was as if the chess experts weren’t thinking so much as reacting. When De Groot listened to their verbal reports, he noticed that they described their thoughts in different language than less experienced chess players. They talked about configurations of pieces like “pawn structures” and immediately noticed things that were out of sorts, like exposed rooks. They weren’t seeing the board as thirty-two pieces. They were seeing it as chunks of pieces, and systems of tension.

Grand masters literally see a different board. Studies of their eye movements have found that they look at the edges of squares more than inexperienced players, suggesting that they’re absorbing information from multiple squares at once. Their eyes also dart across greater distances, and linger for less time at any one place. They focus on fewer different spots on the board, and those spots are more likely to be relevant to figuring out the right move.

But the most striking finding of all from these early studies of chess experts was their astounding memories. The experts could memorize entire boards after just a brief glance. And they could reconstruct longago games from memory. In fact, later studies confirmed that the ability to memorize board positions is one of the best overall indicators of how good a chess player somebody is. And these chess positions are not simply encoded in transient short-term memory. Chess experts can remember positions from games for hours, weeks, even years afterward. Indeed, at a certain point in every chess master’s development, keeping mental track of the pieces on the board becomes such a trivial skill that they can take on several opponents at once, entirely in their heads.

As impressive as the chess masters’ memories were for chess games, their memories for everything else were notably unimpressive. When the chess experts were shown random arrangements of chess pieces—ones that couldn’t possibly have been arrived at through an actual game—their memory for the board was only slightly better than chess novices’. They could rarely remember the positions of more than seven pieces. These were the same chess pieces, and the same chessboards. So why were they suddenly limited by the magical number seven?

The chess experiments reveal a telling fact about memory, and about expertise in general: We don’t remember isolated facts; we remember things in context. A board of randomly arranged chess pieces has no context—there are no similar boards to compare it to, no past games that it resembles, no ways to meaningfully chunk it. Even to the world’s best chess player it is, in essence, noise.

In the same way that a few pages ago we used our knowledge of historic dates to chunk the twelve-digit number, chess masters use the vast library of chess patterns that they’ve cached away in long-term memory to chunk the board. At the root of the chess master’s skill is that he or she simply has a richer vocabulary of chunks to recognize. Which is why it is so rare for anyone to achieve world-class status in chess—or any other field—without years of experience. Even Bobby Fischer, perhaps the greatest chess prodigy of all time, had been playing intensely for nine years before he was recognized as a grand master at age fifteen.

Contrary to all the old wisdom that chess is an intellectual activity based on analysis, many of the chess master’s important decisions about which moves to make happen in the immediate act of perceiving the board. Like the chicken sexer who looks at the chick and simply sees its gender or the SWAT officer who immediately notices the bomb, the chess master looks at the board and simply sees the most promising move. The process usually happens within five seconds, and you can actually see it transpiring in the brain. Using magnetoencephalography, a technique that measures the weak magnetic fields given off by a thinking brain, researchers have found that higher-rated chess players are more likely to engage the frontal and parietal cortices of the brain when they look at the board, which suggests that they are recalling information from long-term memory. Lower-ranked players are more likely to engage the medial temporal lobes, which suggests that they are encoding new information. The experts are interpreting the present board in term of their massive knowledge of past ones. The lower-ranked players are seeing the board as something new.

Though chess might seem like a trivial subject for a psychologist to study—it is, after all, just a game—De Groot believed that his experiments with chess masters had much larger implications. He argued that expertise in “the field of shoemaking, painting, building, [or] confectionary” is the result of the same accumulation of “experiential linkings.” According to Ericsson, what we call expertise is really just “vast amounts of knowledge, pattern-based retrieval, and planning mechanisms acquired over many years of experience in the associated domain.” In other words, a great memory isn’t just a by-product of expertise; it is the essence of expertise.

Whether we realize it or not, we are all like those chess masters and chicken sexers, interpreting the present in light of what we’ve learned in the past, and letting our previous experiences shape not only how we perceive our world, but also the moves we end up making in it.

Too often we talk about our memories as if they were banks into which we deposit new information when it comes in, and from which we withdraw old information when we need it. But that metaphor doesn’t reflect the way our memories really work. Our memories are always with us, shaping and being shaped by the information flowing through our senses, in a continuous feedback loop. Everything we see, hear, and smell is inflected by all the things we’ve seen, heard, and smelled in the past.

In ways as obscure as sexing chickens and as profound as diagnosing an illness, who we are and what we do is fundamentally a function of what we remember. But if interpreting the world and acting in it are rolled up in the act of remembering, what about Ed and Lukas and other mental athletes I’d met? How did this supposedly “simple” technique called the memory palace grant them expert memories without their being experts in anything?

Even if Ericsson and his grad students wouldn’t give me the results of all the tests I spent three days laboring on, I took enough notes on my performance to escape with some sense of where my baseline abilities stood. My digit span was about nine (above average, but nothing extraordinary), my ability to memorize poetry was abysmal, and I had not a clue when Confucius lived (though I did know what a carburetor was for). When I got back from Tallahassee, there was an e-mail waiting in my in-box from Ed:

Hey there star-pupil, I know that you’ve been keeping training to a minimum until after the Florida people have put you through your paces. Very well done—that’s admirable in at least the sense that it will make for better science. But the next championships aren’t a million miles away so you’re going to have to begin preparing yourself pronto. Better get some pep from me now: You need to get your head towards the grindstone and enjoy leaving it there.