How Do You Fight Fair?

In all honesty, I have no idea how to fight fair. When I'm enraged or upset I can't seem to get my mind to catch up with my rapidly moving thoughts. Lately, when I get upset, I just want to run away. So mature. I was trying to figure out why this is. When I was little and would fight with my parents, I'd get mad and run away (and by run away, I mean I'd ride my bike to my friend's house and his mom would call my parents and rat me out). Of course, when my mom got mad at me in the car, she'd drop me off on the side of the road and drive away (she'd circle the block and come back, but still), so perhaps there's a pattern here? Lately I've been having some differences of opinion with my "friend" (who shall remain nameless because that's another topic we won't be covering) and instead of sitting there like a grown-up and trying to talk it through, my first instinct is to get up and leave. What is that? Do other people fight like this? It takes everything in me to stay and talk it through. Of course, I do feel better when it's done, but my heavens. Shouldn't I grow up sooner or later? Why am I such a neverending baby?