It really isn't like that. People always talk about how they'd stop someone else in this rational, considered way. Believe me, as someone who's been on the receiving end of it, it's absolutely nothing like the movies. The first thing is there is a massive shot of adrenaline - suddenly you loose all peripheral vision and most of your hearing. You feel your heart racing. Have you ever tried to play an old video game on a too-fast system? - it's practically uncontrollable, all you can do is lunge around wildly over-controlling until you've got the hang of it? Well, your own body does that to you. It's a little like being drunk in that you're aware of what's in front of you, but very focussed on it to the extent that even quite significant blows will barely be felt. Sometimes you'll look at your aggressor and realise that behind every human being there is an angry ape. You may be aware of entirely inappropriate expressions on your own face - be that a rictus grin, a grimace of terror or scowl of aggression - some people even burst out laughing. The small, rational part of your brain that you usually think on as "you" is - again like being drunk- trying to corale the beast but it's just being drowned out by the rush of blood and the howling of the ancient ape that just woke up. And afterwards you always wonder. Am I me, or am I just a beast pretending to be me?
Some men live for it.