I return to the memory of that moment often, the way we watched and laughed, didn’t think for a second to stop, to interfere, as the man in the Mercedes assaulted someone whose existence he had been so rudely forced to acknowledge. It’s come to shape the way I think about every country, every community: Whose nonexistence is necessary to the self-conception of this place, and how uncontrollable is the rage whenever that nonexistence is violated?