Okay, there was more to it than that. Earlier, he had been around a few I.E.D.s when they lived up to the "E" part of the acronym (close enough to get concussed, but not maimed). He also managed to break both legs and an arm in basic training, and he got shot at a party when he and his friends intervened in a fight. But it was a wall that finally ended his tour -- he took a nasty fall while climbing over it. And that's it. Thanks to what sounds like a deleted scene from Larry the Cable Guy's Delta Farce, Warren was sent home with a spinal brace. Add that to everything else he's been through, along with the general stress of getting shot at for a living, and it's not hard to see how Post-Traumatic Stress Disorder emerged.
Traumatic injury is enough to inspire PTSD for one in five people. So yes, this really is enough.
In the long term, PTSD tends to be self-correcting, because we wouldn't be here today if our distant ancestors had huddled into balls and waited to die the first time a wolf tried to eat them. But 20 percent of traumatized people end up with long-term PTSD, and an inordinate number of them are soldiers. Unlike other traumatic experiences, soldiering produces mixed emotions. Unless the car that put you in a wheelchair for a year was driven by your future spouse, you generally simply want to put traumatic events behind you. But soldiers are usually proud of what they do, and they make good friends while they do it. So you have some of the best moments of your life melded with some of the worst; it's not as simple as "moving on."