Thank you to the woman who chased me for more than a block on this 80°(F) New York City day, just to return the envelope she thought she'd seen me drop. She had, and it contained my pay stub. I had headphones plugged into my ears—they're hard to see—and I was blithely listening to them as I walked to my train. She'd probably been trying to get my attention the whole time, getting more and more frustrated, but she showed no sign of this when she caught up with me. Reminder to self: people are often very kind.