I punched a teenager.
What caused you to punch a teenager?
I think this guy was being a prick because he dared to tell me that my friend is an asshole.
Non-violent methods of resolving conflict achieve the best result and are the best way of resolving conflicts. People involved in conflict should sit together and iron out their differences.
Well I just wanted to hurt him because I wanted to show him that I don't care who he is and what he thinks about me.
Teenagers are still learning how to do the right thing, punching them isn't the way to teach them this. You should have set a good example for them by talking through your disagreement.