“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.”

Malingering amnesia, in which a person fakes symptoms of memory loss, is often associated with attempted financial gain, typically among personal-injury claimants. According to a 2003 study, 29 percent of criminals sentenced to life imprisonment claimed at their trials that they suffered from amnesia. A visual recognition test, such as the Test of Memory Malingering, can be used to detect fraud of this kind.

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.

“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.’ ”