Haven't been in a fight since I left school, a guy stole my camera in Norway years ago, I caught him and punched him, giving him a black eye.
He tried to press charges against me
The police told him they weren't going to pursue it, they also told me that you can't go around hitting people even if they steal from you, fair enough, I agreed with him and apologized, case closed.
Nobody has picked a fight with me since school, not because I am big or strong (I'm not), it's because I don't go looking for a fight, I mind my own business and don't pick on or provoke people, if someone keeps pushing me, I see them as nothing more than a bully, then I have no problem fighting as I believe 100% that I'm in the right, it's easier to fight for something if you believe in it and even if you lose that guy will have his hands full, in a fight it usually comes down to will, not skill, and you thump a bully on the nose you will get his respect.