Its also a great way to create and understand division without actually usually being divided.

Your buddy with a different team will banter with you in a manner that would make most Leftist's head explode, with a level of vitriol and hatred that sometimes can be scary on the outside. But he is still your mate and you learned to accept and throw it back just the same.

The kind of skin thickening and gut ironing that most people are missing since they banned any and all competition or fun in competition from kids.