You've probably never pulled out a knife and demanded someone's watch. That's a good thing, of course, but it illustrates a vital point: Someone who would do such a thing doesn't think like you. Deep down, you probably believe there's a way to resolve a problem without anyone getting hurt. Attackers aren't playing by the same societal rules you are, so you can't react as if they are. All you can ever really do is level the playing field.