You missed my point. And yes even big strong guys like you do get mugged or worse. I don't think its something you can be too confident about. Self defense Is about common sense and luck.
I would put common sense under the umbrella of awareness. As a scientist and mathematician, I would also put luck in the same category of awareness. In any situation, which from the point of view of mathematics I will call a game, as in game theory, luck is about probability. If you are aware of the numbers relevant to your game, and other facts, specifically human factors, you can make luck be on your side. This is what you see with great poker players. How many unknown people with no experience/training have won the world poker tour? This is a legitimate question as I have no idea, but I would be surprised if the number was not zero!
I am about to start a new thread on stats, so I will leave most of the stuff I want to talk about to that.