Watching the reactions and whatnot of the Zimmerman trial has brought one interesting conclusion... Normal people have no idea as to what violence is. They don't experience it, they haven't been confronted by it, and they have not a clue what it is to be on the receiving end of a beating that will only stop when the aggressor wants it to.
Violence is romanticized in movies, boxing, martial arts, and in life in general. If you are not used to violence, you really don't know what it is or what it feels like. Couple this with the fact that fighting, like sex, everyone assumes that they are good at it. They don't know what it feels like to have someone punch them in the face with bad intentions.
What's more, normal people don't know the feeling of helplessness that comes when you realize that this person can do whatever they want to you, and there is no way for you to stop it. This feeling ignites a primal fear deep within a person, it leads to panic. If the aggressor knows how to deal with a panicking opponent, and can remain in a dominant position, it leads the opponent into a very dark despair. They give up.
In Brazilian Jiu-Jitsu, one of the big lessons beginners learn is how to control the feeling of helplessness, the panic, and the despair when nothing you try works. They are taught to overcome these feelings, and work for better position, until they realize where the aggressor's balance points are, and can attack these points intelligently. BUT, in those days, months, and years that the beginner is learning, the fear is very very real, and many people leave the gym because they can't deal with it.
George Zimmerman was mounted. He had an aggressive opponent pounding on his face, and slamming his head in to the pavement. Zimmerman could do nothing to stop the action. I have had people I have had in bad position actually believe that I was going to do them real harm. In the gym. In a controlled environment. Martin and Zimmerman were on the street. I have no doubt that Zimmerman felt in fear for his life or grave bodily injury. I guarantee he felt that way.
I know this because I have been there. Pinned underneath a strong, skilled opponent, and having no ability to escape. I have felt the despair. I remember, vividly, of my first BJJ instructor, Ed, mounted on top of me slapping my face. I reached the point where I just lie there letting it happen. I told him to get off of me. Ed, wanting to teach me a lesson, said: "Fuck you. Make me. I'm gonna slap you like my bitch until you do something. I got all night."
Ed taught me that you always must control your feelings, you always must be looking for a place to attack the balance to escape. Zimmerman did not know this. He felt that he was in his last moments of life. So he pulled his gun and fired.
Those of us who know violence know that it is not pretty. It isn't cool. You don't take punch after punch and walk away smiling. We know of the dead spots in vision that occur, the headaches, the broken bones and bruising. But worst of all we know what it feels like to be in that position where there is no hope of escape.
Zimmerman should have never been in that situation that night. He was a wannabe, with no concept of violence, a couple of MMA classes under his belt, and a gun on his hip. A 6 year old could have taken him. He should have just called in the suspicious person and let it be. He didn't.