The world is sad, Oscar Wilde said, because a puppet was once melancholy. He was referring to Hamlet, a character he thought had taught the world a new kind of unhappiness—the unhappiness of eternal disappointment in life as it is, Weltschmerz. Whether Shakespeare invented it or not, it has proved to be one of the most addictive of literary emotions. Readers consume volumes of it, and then ask to meet the author. It has also proved to be one of the most enduring of literary emotions, since life manages to come up short pretty reliably. Each generation feels disappointed in its own way, though, and seems to require its own literature of disaffection. For many Americans who grew up in the nineteen-fifties, “The Catcher in the Rye” is the purest extract of that mood. Holden Caulfield is their sorrow king.