Now this is something which is misunderstood quite a lot. Almost nobody gets it, though, sometimes not even the doc at the VA. But how could he? He's never been over there. And even if he was over there, he was a desk jockey, a fobbit (you can google that one). Maybe it's best to think of it -- PTSD -- like a switch. And the switch gets turned on when you deploy: The switch that activates the soldier on the battlefield, scanning for threats, vigilant and ready to fight in every situation. Soldier mode -- the mode you love to be in, for all the reasons mentioned in this thread. And then when you get back home, the switch gets turned off: Civilian mode. Once again the civilian slob that goes to the movies and eats a big tub of popcorn. Then when you deploy again, the switch is turned on again: Master of chaos. You come home again, the switch is turned off again: Master of Sunday afternoon naps.
The problem is that at some point, you come home and you realize the switch can't be switched off. It's just a part who you are now. It's now the way you're wired: The first time you go to the movies as a civilian with the switch turned on, you realize you're surrounded by strangers in the darkness for an hour and a half of intense visual and auditory stimulation. Walking down the street to the restaurant, you're actually on patrol, and nothing's more dangerous than a dismounted patrol through the city. You start leaving all the lights on in the house at night, because the things that killed your friends often came out of the darkness. You can't sleep, because of the lights, and because you're hypervigilant and every little noise signals it's time to dispense violence. And if there's one thing that compounds the problem, it's a lack of sleep. This is how you end up in situations where somebody knocks on the door when you're laying on the couch chasing naps that never come, and the mailman smiling at you when you open the door has no idea you're holding a loaded firearm in the hand he can't see. And worse yet, lots of people in this situation drink until they pass out, just to try and get some sleep. But this switch doesn't get turned off when you're drinking at the bar. And on top of that, all the people and all that noise makes things worse, and.......
The problem is that indeed, you've gotten used to it. All of that has been your reality for long enough that you can't turn it off. But our culture has no place for people like this. Our culture is definitely not used to this, and won't get used to this. Relationships cannot handle the strain, so they disintegrate. And employers don't put up with that shit, no matter how cool they are. And lots of people don't try to get help, even in places where the VA normally does a good job and knows how to handle these problems. So in the end, completely alienated by the rest of their communities, some kill themselves. Others end up on the street. Others spend the rest of their lives teetering on the edge of sanity, trying to play a trivial, vapid game with trivial, vapid rules that are always at odds with the life-or-death rules of combat they're wired for. And this is actually why people don't understand unless they've been over there.