I’ve seen this happen so many times either to me or some other guy on the street. Basically you have someone who doesn’t realize that if you walk far enough in one direction without looking where you’re going (especially in New York) you’re going to bump into someone. Perhaps it’s a hot girl they see and don’t want to stop seeing or a fight that’s happening on the street. I don’t know, but it’s never not annoying (when it happens to me) or not amusing (when it happens to someone else and you see it coming from a block away).