In 1995 cognitive psychologist Elizabeth Loftus conducted a study in which she presented to twenty-four people four stories about their childhoods. Three of the stories were true; one was false. Five of the twenty-four people falsely remembered the “lost in a mall” story. “People can be led to remember their past in different ways,” concluded Loftus, “and they even can be led to remember entire events that never actually happened to them.”

“When Simonides or someone offered to teach him the art of memory,” Cicero noted in his De Finibus, the Athenian politician Themistocles “replied that he would prefer the art of forgetting. ‘For I remember,’ said he, ‘even things I do not wish to remember, but I cannot forget things I wish to forget.’ ”

Written in Los Angeles in 1955, the song “Memories Are Made of This” became a number-one hit for Dean Martin. It was a surprise success in Europe, spending four weeks at the top of the UK Singles Chart. A German version, performed by Freddy Quinn and recast as “Heimweh” (“Homesickness”), was the most popular German song of 1956. As “Honvágy-dal” (“The Song of Homesickness”) it became the anthem of the 1956 Hungarian Revolution.

“There is one thing at which I cannot sufficiently wonder,” wrote Pliny the Elder, “that of some trees, the very memory has perished, and even the names recorded by authors have passed out of knowledge.”