Jonathan Yardley writes about some of the great memoirs of the past and the dredge we have clogging the half-priced bookshelves today. He says, “On the one hand, we want ‘authenticity and credibility’ in autobiographical writing; on the other, we want to be entertained, which can sometimes lead writers to exaggeration or invention. . . . [But] what the memoir boom has in fact given us is too many dull or forgettable memoirs, precious few of which have enriched our literature but most of which have simply encouraged the narcissism of their authors.”