This is our nephew Owen...
Owen is 4 years old. Owen has many activities. One that he occasionally enjoys is punching a mini-punching bag in the basement of his house. As he will tell you, his dad has taught him that he's not to hit anyone unless they hit him first.
Well, he was at the public pool the other day. As his father watched, he approached two kids who were playing together to see if he could play with them. One of the kids turned around and hit Owen in the stomach. Owen knew the rules. He'd been hit, so he was free to respond. The kid who hit Owen in the stomach got a fist to the head and was knocked unconscious.
I know I shouldn't be proud of my 4-year old nephew for an act of violence, but I'm glad he stood up for himself. He didn't start the fight, but he finished it and that works for me.