When I first read this, I thought "woah, that's kinda weird and worrying". Then I realised I do something similar. I sometimes rehearse violent confrontations in my imagination.

I've been involved in a few violent confrontations as an adult, and they're nothing like you imagine them to be. People like to imagine all the badass things they would have done in those situations, but when you suddenly find yourself in a brawl, your thoughts are generally "what the hell's going on here? Is this really happening?" I've heard accounts of highly trained martial artists experiencing the same thing. Even if you're physically prepared for a fight, you're not necessarily prepared for the social situation of a fight.

I assume that when I imagine violent first-person scenarios it's some sort of long-term rehearsal process where I'm psychologically preparing myself for conflict at some point in the future. I generally try and avoid situations which have a high risk of physical conflict, though, so my sample size is so small as to be useless when trying to figure out if it does any good.