That is an interesting point. Come to think of it, after that one fight, which wasn't the *** kicking I thought it would be, I took a little bit of crap for getting my nose bloodied but never got challenged to a fight again.
I did also work to transform my body over the summer after that fight and came back to school 35 lbs lighter and hence, maybe less of a target, since I wasn't the fat kid any more. I also changed my attitude a bit. Instead of trying to fit in, I hung out with my friends, and when I wasn't among friends, I kept to myself.
I have no experience with this, but I am told that when men go to prison, they have to fight, or become some other man's girlfriend. They don't have to win, they have to show they have heart. This hyper-machismo environment is an exaggerated version of our society in other ways, particularly young men trying to figure out their place in the world.
In the military, I had to fight to find my place in my unit. After that I did not have to fight my barracks-mates again; nor when I moved from base to base thereafter. Once a reputation is made, it's made, for good or ill. In the Marines, my friends called me 'maddog'. I guess there's a reason for that. It wasn't because I was a great fighter, but it might have been because if I had to fight, I was f'ing nuts.