I don’t take public transit very often, which is a failing—not just environmentally, but also personally, because sometimes that forced contact with the rest of the populated world can be profound. In Japan, many years ago, I was trapped in the small space between train cars by a crowd of schoolboys; my claustrophobia reached such a level that one leg began to judder up and down like the needle on a sewing machine, and the only thing that prevented me from climbing out over the tops of my fellow passengers’ heads was the gaze of a man about a foot away who conveyed calm to me by keeping his eyes trained on mine.