Civilisation, like morals or religion is an artificial construct, a set of rules we like to pretend exist so that we can all run around the same playground without killing each other. Thing is it occasionally breaks down. Often at the weirdest time. Like when you're ordering a cheeseburger.
A man with two young boys cut in line in front of a group of girls at a McDonald's in South LA last night. When one of the young ladies called him on it, presumably in colorful langauge, he beat the crap out of her. The man and the boys then left in a red pickup.
Man, I knew eating that stuff was bad for you. Had no idea ordering it could get you beaten.