A hometown is a place left behind. There are the famous ones: the Garden of Eden, Ithaca, the Shire, Mark Twain’s Hannibal. Those who have moved away carry with them stories of how good it used to be, and of how they can’t go back—not really. Sometimes the place is gone (Eden, for example), but more often, the traveler has changed too much (Odysseus, Frodo, Twain), wedged in too much living, so even in return the place feels distant. What’s left is the rosy past: the old house, the friend knocking on your door after school, the ice-cream truck’s song coming down the street. It’s the way things used to be, whatever that was. “Always it comes when we least expect it, like a wave,” Midwestern bard and Pulitzer Prize winner Charles Wright wrote of nostalgia. “Or like the s...