The aesthetic style associated with Dave Eggers, the memoirist, journalist, novelist, and literary entrepreneur, has always been a slippery thing — instantly recognizable yet somehow difficult to describe. It’s informed not only Eggers’s own writing (he’s most famous for A Heartbreaking Work of Staggering Genius, an account of raising his younger brother after their parents’ sudden death) but a larger literary world, which has gathered itself around periodicals like McSweeney’s and The Believer and their various affiliates. In Eggersland, the persistent aspiration seems to be enthusiasm tempered by self-awareness — a style that’s hortatory but self-deprecating, idealistic but non-dogmatic, childlike …