I posted this on another thread a couple of years ago.
When I was in the 8th grade we had a bully, he bullied everyone. One day we had to stand inline before going into class, he was standing behind me and kept bumping into me on purpose, pushing me. I was in a grumpy mood, turned around and punched him in the mouth, not hard but hard enough that I broke his jaw. He cried like a baby, blood was everywhere, my parents had to pay the medical bills and boy did I get in trouble.
Nobody ever picked on me after that, all the way through high school.