“It’s a poor sort of memory that only works backwards,” wrote Lewis Carroll in Through the Looking Glass. But it’s not true when that backwards-thinking memory is spectacular. Those few with truly eidetic memories, also called photographic memories, have mixed feelings about the power, but there’s no arguing that the ability isn’t incredible. Witness Stephen Wiltshire, an autistic savant and architectural artist who can draw an entire city skyline from memory from just one helicopter ride, or a cathedral after a glance. Or remember the late Kim Peek, the inspiration for Dustin Hoffman’s character in Rain Man, who was estimated to have the complete content of 12,000 books committed to memory. Truly, memory is the library of the mind.
Then there are more or less fortunate people with hyperthymesia, or perfect autobiographical memory. Instead of memorizing the names and numbers of everyone in the phonebook, a person with hyperthymesia can recall with unblinking clarity everything they’ve ever experienced in their life. There have only been six documented cases of hyperthymesia in the world, but in each case, the patient can remember every detail of every day they’ve lived: what color shirt they wore, the faces of people who passed them in traffic, the arbitrary shapes of clouds. Every slight, every embarrassment, every victory, every heartbreaking moment. Forgetfulness is the gardener of memory, and hyperthymetics live in an unweeded wilderness of places, times, and emotions. In Jorge Luis Borges’ short story Funes el memorioso, the author invents a character with such a remarkable memory that he can relive a previous day’s events in real time, which, of course, takes an entire day to do. Funes is cursed by the inability to understand abstractions; able to remember absolutely every experience in crystal clear detail, he cannot understand the need to generalize. Poetry and dreams are beyond him. Every moment in the past is just as real to him as the current one, and his life one unbroken and contiguous chain of events interrupted only by sleep.
I remember a man on the streets of Prague who would make money from tourists by betting them that he could tell them their area code with only the name of their hometown. What I didn’t realize then was that anyone is capable of such feats of memorization, with practice. Mnemonists can memorize the sequence of a deck of shuffled playing cards in under 25 seconds, or the names of 1,500 conference attendees after hearing them once. Humans can do this by the use of mnemonic devices: acronyms, memory journeys, and storytelling. Our species is lousy at remembering abstractions — the opposite of memory, you’ll recall — but pretty good at remembering images and places. So a mnemonist will associate numbers (which are abstract concepts) with pictures and turn the first 100,000 decimal places of pi into a kind of mental comic book. Or they will take every line from The Iliad, turn each line into an image, and store each image somewhere in a “memory palace” (the remembrance of a well-known building, like one’s home) where the images can be “collected” in sequence. The spatial memory that helps you navigate your world is actually pretty keen; we lab rats have figured out the maze of our own construction quite nicely. But when it comes to spatial memory, there’s at least one animal who makes humans look like babes in the woods.
You look a little lost, dear.