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

The Memory Palace

I had arranged to get together with Ed one last time before he headed back to Europe. He wanted to meet me in Central Park, which he had never seen before, and which he insisted was a vital stop on his tour of America. After taking in the bare late-winter trees and watching the runners do their midday laps around the Reservoir, we ended up at the southern end of the park, directly across the street from the Ritz-Carlton Hotel. It was a frigid and brutally windy afternoon—less than ideal conditions for thinking of any kind, much less memorizing. Nevertheless, Ed insisted that we remain outdoors. He handed me his cane and gamely clambered up one of the big boulders near the edge of the park, with what appeared to be some pain in his chronically arthritic joints. After scanning the horizon and commenting on the “perfect sublimity” of the spot, he invited me to join him on top of the rock. He had promised that he could teach me a few basic memory techniques in under an hour. It was hard to imagine we could brave the weather for any longer than that.

“I have to warn you,” Ed said, as he delicately seated himself crosslegged, “you are shortly going to go from having an awed respect for people with a good memory to saying, ’Oh, it’s all a stupid trick.’ ” He paused and cocked his head, as if to see if that would in fact be my response. “And you will be wrong. It’s an unfortunate phase you’re just going to have to pass through.”

He started his lesson with the most basic principle of all mnemonics: “elaborative encoding.” Our memories weren’t built for the modern world, he explained. Like our vision, our capacity for language, our ability to walk upright, and every other one of our biological faculties, our memories evolved through a process of natural selection in an environment that was quite different from the one we live in today.

Most of the evolution that shaped the primitive brains of our prehuman ancestors into the linguistic, symbolic, neurotic modern brains that serve us (sometimes poorly) today took place during the Pleistocene, an epoch which began about 1.8 million years ago and only ended ten thousand years ago. During that period—and in a few isolated places, still to this day—our species made its living as huntergatherers, and it was the demands of that lifestyle that sculpted the minds we have today.

Much as our taste for sugar and fat may have served us well in a world of scarce nutrition, but is now maladaptive in a world of ubiquitous fast food joints, our memories aren’t perfectly adapted for our contemporary information age. The tasks that we often rely on our memories for today simply weren’t relevant in the environment in which the human brain evolved. Our ancestors didn’t need to recall phone numbers, or word-for-word instructions from their bosses, or the Advanced Placement U.S. history curriculum, or (because they lived in relatively small, stable groups) the names of dozens of strangers at a cocktail party.

What our early human and hominid ancestors did need to remember was where to find food and resources, and the route home, and which plants were edible and which were poisonous. Those are the sorts of vital memory skills that they depended on every day, and it was—at least in part—in order to meet those demands that human memory evolved as it did.

The principle underlying all memory techniques is that our brains don’t remember all types of information equally well. As exceptional as we are at remembering visual imagery (think of the two-picture recognition test), we’re terrible at remembering other kinds of information, like lists of words or numbers. The point of memory techniques is to do what the synasthete S did instinctually: to take the kinds of memories our brains aren’t good at holding on to and transform them into the kinds of memories our brains were built for.

“The general idea with most memory techniques is to change whatever boring thing is being inputted into your memory into something that is so colorful, so exciting, and so different from anything you’ve seen before that you can’t possibly forget it,” Ed explained to me between breaths into his clenched fists. “That’s what elaborative encoding is. In a moment, we’re going to do this with a list of words, which is just a sort of general exercise for getting ahold of the techniques. Then you’re going to be able to move on to numbers, playing cards, and then, from there, to complex concepts. Basically, when we’re done with you, you’re going to be able to learn anything you want to, really.”

Ed recounted how on a recent visit to Vienna, he and Lukas had partied until dawn the night before Lukas’s biggest exam of the year, and only stumbled home just before sunrise. “Lukas woke up at noon, learned everything for the exam in a memory blitz, and then passed it,” said Ed. “When you’re that effective at learning, it’s a bit of a temptation to not bother oneself with feelings of academic guilt until the last possible moment. Lukas has figured out that effort is a rather vulgar exercise.”

Ed tucked his curls behind his ears, and asked me what I wanted to memorize first. “We could start by learning something useful, like the Egyptian pharaohs or the terms of the American presidents,” he offered. “Or perhaps a Romantic poem? We could do the geological epochs, if you’d like.”

I laughed. “That all sounds very useful.”

“We could quickly learn all the American football winners for the last century or so, or the point averages of the top baseball stars, if you’d like.”

“Do you know—really know—all the winners of the Super Bowl?” I asked.

“Well, no, I don’t. I prefer cricket. But I’d be happy to teach them to you. That’s the point: We can quickly learn anything with these techniques. Look, you tempted or not?”

“I’m tempted.”

“Well, I suppose the most obvious, practical use of this technique is the mastery of one’s to-do list. Do you keep a to-do list?”

“At home, yes. Sort of. From time to time.”

“I see. Well, I keep a to-do list in my memory at all times. We’ll use mine.”

Ed asked for a piece of paper, which he then scribbled a few words on. He handed it back to me with a mischievous smirk. It was a list of fifteen items. “Just a few things I’ve got to get done around town before I head upstate for a party a friend of mine is throwing,” he said.

I read the list aloud:

Pickled garlic

Cottage cheese

Salmon (peat-smoked if poss.)

Six bottles of white wine

Socks (x3)

Three hula-hoops (spare?)

Snorkel

Dry ice machine

E-mail Sophia

Skin-toned cat suit

Find Paul Newman film—Somebody Up There Likes Me

Elk sausages??

Megaphone and director’s chair

Harness and ropes

Barometer

“This list is from your memory?” I asked incredulously.

“From my memory it came. Into your memory it shall go,” said Ed.

“And this is serious?”

“Well, I’m not sure if I’ll be able to find everything on it. Do you have cottage cheese in New York?”

“I’m a little more concerned about the elk sausages and the skin-toned cat suit,” I told him. “And besides, aren’t you leaving town to go back to England tomorrow?”

“Yes, well, I’m prepared to accept that many of these items aren’t absolutely necessary.” He winked. “The point of this exercise, however, is that you are going to commit this list to memory.”

Ed told me that by learning the techniques he was about to teach, I would be installing myself in a “proud tradition of mnemonists.” That proud tradition began, at least according to legend, in the fifth century B.C. with the poet Simonides of Ceos standing in the rubble of the great banquet hall collapse in Thessaly. As the poet closed his eyes and reconstructed the crumbled building in his imagination, he had an extraordinary realization: He remembered where each of the guests at the ill-fated dinner had been sitting. Even though he had made no conscious effort to memorize the layout of the room, it had nevertheless left a durable impression upon his memory. From that simple observation, Simonides reputedly invented a technique that would form the basis of what came to be known as the art of memory. He realized that if it hadn’t been guests sitting at the banquet table, but rather something else—say, every great Greek dramatist seated in order of their dates of birth—he would have remembered that instead. Or what if, instead of banquet guests, he saw each of the words of one of his poems arrayed around the table? Or every task he needed to accomplish that day? Just about anything that could be imagined, he reckoned, could be imprinted upon one’s memory, and kept in good order, simply by engaging one’s spatial memory in the act of remembering. To use Simonides’ technique, all one has to do is convert something unmemorable, like a string of numbers or a deck of cards or a shopping list or Paradise Lost, into a series of engrossing visual images and mentally arrange them within an imagined space, and suddenly those forgettable items become unforgettable.

Virtually all the nitty-gritty details we have about classical memory training—indeed, nearly all the memory tricks in the mental athlete’s arsenal—were first described in a short, anonymously authored Latin rhetoric textbook called the Rhetorica ad Herennium, written sometime between 86 and 82 B.C. It is the only truly complete discussion of the memory techniques invented by Simonides to have survived into the Middle Ages. Though the intervening two thousand years have seen quite a few innovations in the art of memory, the basic techniques have remained fundamentally unchanged from those described in the Ad Herennium. “This book is our bible,” Ed told me.

Ed reads both Latin and ancient Greek (as well as speaking French and German fluently) and fancies himself an amateur classicist. The Ad Herennium was to be the first of several ancient texts he pressed upon me. Before I sampled Tony Buzan’s expansive oeuvre (he’s authored or coauthored over 120 books) or any of the self-help books put out by the top mental athletes, Ed wanted me to start my investigation with the classics. In addition to the Ad Herennium, there would be translated excerpts of Quintilian’s Institutio Oratoria and Cicero’s De Oratore for me to read, followed by a collection of medieval writings on memory by Thomas Aquinas, Albertus Magnus, Hugh of St. Victor, and Peter of Ravenna.

The techniques introduced in the Ad Herennium were widely practiced in the ancient world. In fact, in his own writings on the art of memory, Cicero says that the techniques are so well known that he felt he didn’t need to waste ink describing them in detail (hence our reliance on the Ad Herennium). Once upon a time, every literate person was versed in the techniques Ed was about to teach me. Memory training was considered a centerpiece of classical education in the language arts, on par with grammar, logic, and rhetoric. Students were taught not just what to remember, but how to remember it.

In a world with few books, memory was sacrosanct. Just look at Pliny the Elder’s Natural History, the first-century encyclopedia that chronicled all things wondrous and useful for winning bar bets in the classical world, including the most exceptional memories then known to history. “King Cyrus could give the names of all the soldiers in his army,” Pliny reports. “Lucius Scipio knew the names of the whole Roman people. King Pyrrhus’s envoy Cineas knew those of the Senate and knighthood at Rome the day after his arrival ... A person in Greece named Charmadas recited the contents of any volumes in libraries that anyone asked him to quote, just as if he were reading them.” There are plenty of reasons not to take everything Pliny says at face value (he also reported the existence of a race of dog-headed people in India) but the sheer volume of anecdotes about extraordinary memories in the classical world is itself telling. Seneca the Elder could repeat two thousand names in the order they’d been given to him. St. Augustine tells of a friend, Simplicius, who could recite Virgil by heart—backward. (That he could recite it forward seems to have been unremarkable.) A strong memory was seen as the greatest virtue since it represented the internalization of a universe of external knowledge. “Ancient and medieval people reserved their awe for memory. Their greatest geniuses they describe as people of superior memories,” writes Mary Carruthers, the author of two books on the history of memory techniques. Indeed, the single most common theme in the lives of the saints—besides their superhuman goodness—is their often extraordinary memories.

The Ad Herennium’s discussion of memory—“that treasure-house of inventions and the custodian of all parts of rhetoric”—is actually quite short, about ten pages embedded in a far longer treatise on rhetoric and oration. It begins by making a distinction between natural memory and artificial memory: “The natural memory is that memory which is embedded in our minds, born simultaneously with thought. The artificial memory is that memory which is strengthened by a kind of training and system of discipline.” In other words, natural memory is the hardware you’re born with. Artificial memory is the software you run on your hardware.

Artificial memory, the anonymous author continues, has two basic components: images and places. Images represent the contents of what one wishes to remember. Places—or loci, as they’re called in the original Latin—are where those images are stored.

The idea is to create a space in the mind’s eye, a place that you know well and can easily visualize, and then populate that imagined place with images representing whatever you want to remember. Known as the “method of loci” by the Romans, such a building would later come to be called a “memory palace.”

Memory palaces don’t necessarily have to be palatial—or even buildings. They can be routes through a town—as they were for S—or station stops along a railway, or signs of the zodiac, or even mythical creatures. They can be big or small, indoors or outdoors, real or imaginary, so long as there’s some semblance of order that links one locus to the next, and so long as they are intimately familiar. The four-time U.S. memory champion Scott Hagwood uses luxury homes featured in Architectural Digest to store his memories. Dr. Yip Swee Chooi, the effervescent Malaysian memory champ, used his own body parts as loci to help him memorize the entire 56,000-word, 1,774-page Oxford Chinese-English dictionary. One might have dozens, hundreds, perhaps even thousands of memory palaces, each built to hold a different set of memories.

In Australia and the American Southwest, Aborigines and Apache Indians independently invented forms of the loci method. But instead of using buildings, they relied on the local topography to plot their narratives, and sang them across the landscape. Each hillock, boulder, and stream held a part of the story. “Myth and map became coincident,” says John Foley, a linguistic anthropologist at the University of Missouri who studies memory and oral traditions. One of the tragic consequences of embedding narrative into the landscape is that when Native Americans had land taken from them by the U.S. government, they lost not only their home but their mythology as well.

“The thing to understand, Josh, is that humans are very, very good at learning spaces,” Ed remarked from his perch on the boulder. “Just to give an example, if you are left alone for five minutes in someone else’s house you’ve never visited before, and you’re feeling energetic and nosy, think about how much of that house could be fixed in your memory in that brief period. You’d be able to learn not just where all the different rooms are and how they connect with each other, but their dimensions and decoration, the arrangement of their contents, and where the windows are. Without really noticing it, you’d remember the whereabouts of hundreds of objects and all sorts of dimensions that you wouldn’t even notice yourself noticing. If you actually add up all that information, it’s like the equivalent of a short novel. But we don’t ever register that as being a memory achievement. Humans just gobble up spatial information.”

The principle of the memory palace, he continued, is to use one’s exquisite spatial memory to structure and store information whose order comes less naturally—in this case, Ed’s to-do list. “What you’re going to find is that in the same way as it’s impossible to get confused about the order of rooms in that house, it will be equally obvious that immediately after I locate three hula hoops, a snorkel, and a dry ice machine, my next task will be e-mailing my friend Sophia.”

The crucial thing was to choose a memory palace with which I was intimately familiar. “For your first memory palace, I’d like you to use the house you grew up in, since that’s a space you’re likely to know very well,” Ed said. “We’re going to array the items of my to-do list one by one along a route that will snake around your childhood home. When it comes time to recall the list, all you will need to do is retrace the steps we’re about to take in your imagination. The hope is that all the objects you’re about to memorize will pop back into mind. Now, tell me, is your childhood home a bungalow?”

“More of a two-story brick house,” I said.

“Does it have a cute postbox at the end of the driveway?”

“No. Why?”

“Shame. That would be an excellent first locus at which to deposit an image of the first item on our to-do list. But that’s okay. We can start at the foot of the driveway. I want you to close your eyes and try to visualize in as much detail as possible a large bottle of pickled garlic standing right where the car should be parked.”

I wasn’t entirely sure what I was supposed to be visualizing. “What is pickled garlic? Is that, like, an English delicacy?” I asked.

“Um, no, it’s just the sort of snack one brings along for a weekend out in the mountains.” He flashed another impish grin. “Now, it’s very important to try to remember this image multisensorily.” The more associative hooks a new piece of information has, the more securely it gets embedded into the network of things you already know, and the more likely it is to remain in memory. Just as S spontaneously and involuntarily turned every sound that passed through his ears into a chorus of colors and smells, the author of the Ad Herennium urged his readers to do the same with every image they wanted to remember.

“It’s important that you deeply process that image, so you give it as much attention as possible,” Ed continued. “Things that grab our attention are more memorable, and attention is not something you can simply will. It has to be pulled in by the details. By laying down elaborate, engaging, vivid images in your mind, it more or less guarantees that your brain is going to end up storing a robust, dependable memory. So try to imagine the pleasant smell of the pickled garlic, and exaggerate its proportions. Imagine tasting it. Really let the flavor roll around on your tongue. And make sure you see yourself doing this at the foot of your driveway.” If I didn’t know what pickled garlic was, I was even less sure of how it tasted. Nevertheless, I imagined a large bottle of the stuff standing proudly at the foot of my parents’ driveway.

(I’d encourage you, reader, to do the same along with me. Try imagining a bottle of pickled garlic at the foot of your own driveway, or if you don’t have a driveway, someplace else outside your home. Really try to visualize it.)

“Now that you’ve installed a complete multisensorial picture of pickled garlic, we’re going to walk up the path to your home and visualize the next item on our to-do list at the front door. It’s cottage cheese. I want you to close your eyes and see an enormous wading-pool-size tub of cottage cheese. Have you got it?

“I think so.”

(Have you?)

“Now I want you to imagine Claudia Schiffer swimming in this tub of cottage cheese. I want you to imagine her swimming in the buff, and dripping with dairy. Are you picturing this? I don’t want you to miss any of the details here.”

The Ad Herennium advises readers at length about creating the images for one’s memory palace: the funnier, lewder, and more bizarre, the better. “When we see in everyday life things that are petty, ordinary, and banal, we generally fail to remember them, because the mind is not being stirred by anything novel or marvelous. But if we see or hear something exceptionally base, dishonorable, extraordinary, great, unbelievable, or laughable, that we are likely to remember for a long time.”

The more vivid the image, the more likely it is to cleave to its locus. What distinguishes a great mnemonist, I was learning, is the ability to create these sorts of lavish images on the fly, to paint in the mind a scene so unlike any that has been seen before that it cannot be forgotten. And to do it quickly. Which is why Tony Buzan tells anyone who will listen that the World Memory Championship is less a test of memory than of creativity.

When forming images, it helps to have a dirty mind. Evolution has programmed our brains to find two things particularly interesting, and therefore memorable: jokes and sex—and especially, it seems, jokes about sex. (Do you remember what Rhea Perlman and Manute Bol were doing on the first page of this book?) Even memory treatises from comparatively prudish eras make this point. Peter of Ravenna, author of the most famous memory textbook of the fifteenth century, first asks the pardon of chaste and religious men before revealing “a secret which I have (through modesty) long remained silent about: if you wish to remember quickly, dispose the images of the most beautiful virgins into memory places; the memory is marvelously excited by images of women.”

I was finding it a little hard to get excited about Claudia Schiffer and her tub of cottage cheese, however. My nose and ears were stinging from the icy wind. “Um, Ed, should we maybe take this lesson inside somewhere?” I asked. “There must be a Starbucks around here.”

“No, no. This cold air is good for the brain,” he said. “Now pay attention. We’ve just walked inside the door of your house. I want you to turn to the left in your mind’s eye. What’s the next room you enter into?” he asked.

“The living room. There’s a piano in it.”

“Perfect. Our third item is peat-smoked salmon. So let’s imagine that underneath the strings of this piano there’s a lot of smoking peat. And lying on top of the piano strings, there is a Hebridean salmon. Ooooh ... can you smell that?” He whiffed at the cold air.

Again, I wasn’t certain what peat-smoked salmon was, but it sounded like lox, so that’s what I visualized. “Smells great,” I said, my eyes still closed.

(If you don’t have a piano in your own home, just put the peat-smoked salmon somewhere to the left of your front door.)

The next item on the list was six bottles of white wine, which we decided to place on the stained white couch next to the piano.

“Now, anthropomorphizing the bottles of wine is quite a good idea,” Ed suggested. “Animate images tend to be more memorable than inanimate images.” That advice, too, came from the Ad Herennium. The author instructs his readers to create images of “exceptional beauty or singular ugliness,” to put them into motion, and to ornament them in ways that render them more distinct. One could “disfigure them, as by introducing one stained with blood or soiled with mud or smeared with red paint,” or else proceed by “assigning certain comic effects to our images.”

“Perhaps you should imagine the wines discussing their relative merits among themselves,” Ed suggested.

“So, like, Mr. Merlot is saying—”

“Merlot is not a white wine, Josh,” he interrupted, with a bemused titter. “Rather, let’s imagine that the chardonnay is plaintively insulting the soil quality of the sauvignon blanc, while the gewürztraminer is giggling away nearby at the expense of the rieslings ... That sort of thing.”

I thought that was a funny image, and one sure to stick in my mind. But why? What makes six snooty, anthropomorphized wine bottles more memorable than the words “six bottles of wine”? Well, for one thing, visualizing such an outlandish image demanded more mental indulgence than simply reading four words. In the process of expending all that mental effort, I was forming more durable connections among the neurons that would encode that memory. But even more important, the memorableness of those talking wine bottles is a function of their novelty. While I have seen many wine bottles in my day, I have never seen one that talks before. Were I to simply try to remember the words “six bottles of wine,” that memory would soon blend in with all my other memories of wine bottles.

Consider: How many of the lunches that you ate over the last week can you recall? Do you remember what you ate today? I hope so. Yesterday? I bet it takes a moment’s effort. And what about the day before yesterday? What about a week ago? It’s not so much that your memory of last week’s lunch has disappeared; if provided with the right cue, like where you ate it, or whom you ate it with, you would likely recall what had been on your plate. Rather, it’s difficult to remember last week’s lunch because your brain has filed it away with all the other lunches you’ve ever eaten as just another lunch. When we try to recall something from a category that includes as many instances as “lunch” or “wine,” many memories compete for our attention. The memory of last Wednesday’s lunch isn’t necessarily gone; it’s that you lack the right hook to pull it out of a sea of lunchtime memories. But a wine that talks: That’s unique. It’s a memory without rivals.

“Next along on our list we have three pairs of socks,” Ed continued. “Maybe there’s a lamp you can hang them on nearby?”

“Yeah, there’s a lamp right next to the couch,” I said.

(If you’re still following along, you should be putting those six bottles of wine and three pairs of socks somewhere in the first room of your house.)

“Splendid. Now, I know of precisely two ways to make socks attention-grabbing. One is to have them be appallingly old and smelly. The other is to make them those incredible socks made of cotton in nice colors that you can never really find. Let’s make these socks the latter. So I’d like you to just see them dangling there on the lamp. And since it’s often good to have a bit of supernatural crap going on, too, perhaps you can imagine that there is an elegant ghost inside the socks that is stretching and pulling them. Really try to see it. Imagine the feeling of those soft cotton socks coolly brushing against your forehead.”

I followed Ed like this around my childhood home, dropping images along the way as I sauntered from room to room in my imagination. In the dining room, I visualized three hula-hooping women on top of the table. Stepping into the kitchen, I saw a man wearing a snorkel diving into the sink, and a dry-ice machine blowing smoke across the counter. (Are you keeping up?) From there, I moved into the den. The next item on the list was “e-mail Sophia.”

I unclenched my eyes to ask Ed for help, and watched him licking the edge of a rolling paper for a fresh cigarette. “What should ’e-mail Sophia’ look like?” I asked.

“Ooh, that’s a tough one,” he said, putting down his cigarette. “You see, e-mail isn’t very memorable in itself. The more abstract the word, the less memorable it is. We need to make e-mail concrete somehow.” Ed paused and thought on it for a moment. “What I’d like to propose is that you imagine a she-male sending the e-mail. Can you do that? And you’ll need to associate that she-male with Sophia. What’s the first image that enters your mind when I say the word ’Sophia’ ? ”

“It’s the capital of Bulgaria,” I said.

“That’s very educated of you, Josh. Bravo. But, alas, not very memorable. Instead let’s make it Sophia Loren. And let’s have her sitting on the lap of the she-male as she/he types away at the computer. Have you visualized it? Are you sufficiently engaged by this image? Splendid.”

The pace of image-making now picked up. I left the den and visualized a comely woman in a skin-toned cat suit purring in the hallway. I placed Paul Newman in a nearby alcove, and an elk at the top of the stairs to the basement. I walked down the stairs and into the garage, where I left behind an image of Ed sitting in a director’s chair barking orders through a giant megaphone. Then I imagined myself pressing the clicker that raises the garage door and walking out into the backyard, where a harnessed climber was using ropes to ascend a sizable oak tree. And the final image, a barometer, was installed alongside the backyard fence. “To remind you that it’s a BAR-ometer, you should see a thermometerlike column sitting in a bed of pork scratchings and other bar snacks,” Ed helpfully suggested. Having completed my circuit of the house, I opened my eyes.

“Well done,” Ed said, with slow and deliberate applause. “Now, I think you’re going to find that the process of recalling these memories is incredibly intuitive. See, normally memories are stored more or less at random in semantic networks, or webs of association. But you have now stored a large number of memories in a very controlled context. Because of the way spatial cognition works, all you have to do is retrace your steps through your memory palace, and hopefully at each point the images you laid down will pop back into your mind as you pass by them. All you’ll have to do is translate those images back into the things you were trying to learn in the first place.”

I closed my eyes again and saw myself back at the foot of my parents’ driveway. The enormous jar of pickled garlic was just where I’d left it. I walked up the path to the front door. There was Claudia Schiffer, seductively scrubbing herself with a sponge in a tub of cottage cheese. I opened the door and turned to the left, and inhaled a noseful of the fish that was still laid out across the strings of the piano, curing in peat smoke. I felt its flavor on my tongue. I could hear the highpitched chatter of those haughty wine bottles on the couch, and feel the three pairs of luxurious cotton socks on the lamp brushing softly against my forehead. I couldn’t believe it was really working. I called out the first five items of the to-do list for Ed to confirm. “Pickled garlic! Cottage cheese! Peat-smoked salmon! Six bottles of wine! Three pairs of socks!”

“Exceptional!” Ed shouted into the cold wind. “Exceptional! The makings of KL7 material here!”

Well, I knew my performance couldn’t have been that exceptional, given the much more impressive feats I’d witnessed the day before. Still, I was feeling pretty good about my accomplishment. I continued walking through the house, picking up the bread crumbs of exotic images I’d deposited earlier. “Three hula hoops on the dining room table! Snorkel in the sink! Dry ice machine on the counter!” To my surprise and delight, all fifteen images were exactly where I’d left them. But would those memories really stick, I wondered? A week from now, would I still remember Ed’s to-do list?

“Barring an episode of binge drinking or a wallop to the side of your head, you’re going to find that those images will hold in your mind far longer than you might expect,” Ed promised me. “And if you revisit the journey through your memory palace later this evening, and again tomorrow afternoon, and perhaps again a week from now, this list will leave a truly lasting impression. And having now done this with fifteen words, we could easily do it with fifteen hundred, provided you had an appropriately large memory palace to store them in. And then having mastered random words, we can move onto the truly fun stuff, like playing cards and Heidegger’s Being and Time.”