First big concussion I got was me walking home at night. I was living right in the centre of town, a few minutes from a grocery store. You know, like how people on HN moralise we should all do.

Three people jumped out of a car, beat me up and left. It was a gang initiation thing - beat up a random civilian and get to the first rank, or something. After that concussion I was a lot more susceptible to other concussions.

Can't make an NYC analogue - do people feel safe there walking at all hours of the night by themselves, even in dark areas? If so great, maybe that's a place I'd live too, like Tokyo or Taipei.