I'm 72, only 5'7' and 150 pounds. I trained in hard style Karate for about five years and learned some important things:

1. In hand to hand combat, I will never beat some guy who grew up fighting for lunch money every day on the street.
2. Situational awareness is more important fighting skills. A fight avoided is a fight won. Run away if I can.
3. Don't go to stupid places and do stupid things with stupid people.
4. If all else fails, shoot to stop the threat.