In “Permutation City”, a novel by Greg Egan, the character Peer, having achieved immortality within a virtual reality over which he has total control, finds himself terribly bored. So he engineers himself to have new passions. One moment he is pushing the boundaries of higher mathematics; the next he is writing operas. “He’d even been interested in the Elysians [the afterlife], once. No longer. He preferred to think about table legs.” Peer’s fickleness relates to a deeper point. When technology has solved humanity’s deepest problems, what is left to do?