This is a book about the end of childhood. Much of it is drawn directly from a diary the author kept while he was a bright but insecure freshman at Harvard in the 1950s. From these pages emerges a precise description of the raw, half-understood experience of late adolescence-the anguish and arguments, the rivalry and anxiety about sex, the facile cynicism and desperate fumblings for purpose, the bull sessions held late at night-just as Peter Prescott...