For many people — particularly anyone over the age of 30 — the idea of describing your blow-by-blow activities in such detail is absurd. Why would you subject your friends to your daily minutiae? And conversely, how much of their trivia can you absorb? The growth of ambient intimacy can seem like modern narcissism taken to a new, supermetabolic extreme — the ultimate expression of a generation of celebrity-addled youths who believe their every utterance is fascinating and ought to be shared with the world.