Some memorizers arbitrarily associate each playing card with a familiar person or object, so that the king of clubs is represented by, say, Tony Danza. The grand masters associate each card with a person, an action, or an object so that every group of three cards can be converted into a sentence.
Joshua FoerIf you were a medieval scholar reading a book, you knew that there was a reasonable likelihood you'd never see that particular text again, and so a high premium was placed on remembering what you read. You couldn't just pull a book off the shelf to consult it for a quote or an idea.
Joshua FoerTo attain the rank of grand master of memory, you must be able to perform three seemingly superhuman feats. You have to memorize 1,000 digits in under an hour, the precise order of 10 shuffled decks of playing cards in the same amount of time, and one shuffled deck in less than two minutes. There are 36 grand masters of memory in the world.
Joshua Foer