Mnemosyne—Titaness and personification of memory in Greek mythology—was mother to the Muses; her nine consecutive nights of coition with Zeus produced lyric poetry, history, music, tragedy, astronomy, and so on. Memory, like the Muses themselves, will not always perform on command; trying to recall a past event doesn’t necessarily get one very far. But, as Marcel Proust knew, occasionally the past comes back unbidden and more vividly than if it had been consciously called up. Proust’s famous episode at the beginning of À la recherche du temps perdu captures young Marcel’s experience of this kind of “involuntary memory”:
I raised to my lips a spoonful of the tea in which I had soaked a morsel of the cake. No sooner had the warm liquid mixed with the crumbs touched my palate than a shudder ran through me and I stopped, intent upon the extraordinary thing that was happening to me. An exquisite pleasure had invaded my senses, something isolated, detached, with no suggestion of its origin. And at once the vicissitudes of life had become indifferent to me, its disasters innocuous, its brevity illusory—this new sensation having had on me the effect which love has of filling me with a precious essence; or rather this essence was not in me, it was me.
Depending on the person, involuntary memory—the sense that one has not merely recalled a feeling but is the feeling—can extend to the darker emotions as well: hate, anger, dread, guilt. These