Fighting is hardly a good reaction to any situation (of course the exception being the people who do it for a living, in which case, more power to you if you can stand getting your shit kicked as a profession). Almost every time I was in a fight, it was because it was the only option I had to not get seriously hurt.
It sucks, because I'm a big guy by nature. It's in the genes. I have a wide frame, a seriously dense bone structure and naturally big muscles to carry the extra weight. Because of this, every dick with a chip on his shoulder has tried his hand at taking me on. I was in half a dozen fights in high school that I never wanted to be in, and a few since then, only one of which was I was actively defending someone other than myself.
I'll fight when I have to, especially when it comes to attempting to help someone I care about, but as the goody goodies say, it's a last resort, when I've exhausted my other options.