Say it's Monday and it's a bad one. You overslept and definitely didn't shower, so your hair might smell and maybe you spill some coffee on your shirt while you're barreling toward the Metro, which is especially unfortunate because you're meeting with your boss at 9:30.
Just when you think your bloodstream has reached maximum cortisol saturation, a slow-moving elderly man steps between you and the train doors. Then he drops his wallet. Do you rush past him because you're too stressed to deal and there are plenty of other people around to step up — or do you help the guy out?