Well, I don't post much here, but I thought I'd weigh in just for the heck of it.
If you think about it there are really only a couple of reasons that people 'pick' fights....not to be confused with a genuinely heated conflict.
1. Respect. They want to be respected, primarily by their friends. This is a sign of low self confidence. You need to be secure in yourself. When you achieve that there is no need to prove it to others.
2. To test themselves. People, especially young guys, want to know that they can hold up in the heat of combat.
Testing yourself against an untrained opponent doesn't prove much. You either win (might as well be picking on a smaller kid because he's untrained), or you get beat, in which case you're hurt, and possibly unable to train for a while...it's really easy to break your hands!
3. A few guys just like to hurt people. That sucks.
Certainly there is something to be gained from sparring full contact. Protect yourself. It would be foolish to take yourself out of the training game because you got a concussion, or broke something.
As far as being the 'toughest' kid in school....in the end you're just that...a kid in school....not a man. Real men don't need to prove their toughness by fighting like animals.
My 2 cents