One of the strongest motivations for rereading is purely selfish: it helps you remember what you used to be like. Open an old paperback, spangled with marginalia in a handwriting you outgrew long ago, and memories will jump out with as much vigor as if you'd opened your old diary. These book-memories, says Hazlitt, are 'pegs and loops on which we can hang up, or from which we can take down, at pleasure, the wardrobe of a moral imagination, the relics of our best affections, the tokens and records of our happiest hours.' Or our unhappiest. Rereading forces you to spend time, at claustrophobically close range, with your earnest, anxious, pretentious, embarrassing former self, a person you thought you had left behind but who turns out to have been living inside you all along.