Turns out that Blue Shirt Guy works for my company, in another building — I had seen his name in various emails, but I don't think I'd ever met him in person before. The upshot is I got to thank him for looking out for me yesterday, which was really nice. I sent him an email, and he called to check up on me this afternoon. Also, he confirmed that it was the lamp post I hit with my leg, and not the post box. I kind of thought that was the case.
I suspect that most of us are kinder on average than we think we are.
Right now, I'm actually feeling pretty darned good about the human race.