A long time ago I was in my late 20s in a bar in Tampa. There was a guy there - shaved head, covered in Tats, maybe 6'2" and 160lbs. He started talking to my GF. So I call him on it. He sincerely apologizes, said he thought she was alone and that he didn't want any trouble with me. I am really that menacing!
So I show pity and don't beat his ass to the ground. We start talking, he really is a nice guy. He is also a Marine Recon who just returned from Gulf War 1. Among other things he showed me how easy it is to snap someone's C3, C4 (whatever) vertebra.
You never know when you are gonna run into one of these guys. Anyone here think they would be afraid of BJ Penn if they didn't know him? Not me.