I used to work with a very quiet, very shy guy who turned out to be a legal immigrant from Iran.
As we became friends, he told me he was a veteran of the Iran-Iraq war, then some of his experiences. It was the stuff of waking, screaming nightmares. He'd been gassed, forcing him up from the trenches, only to fall victim to nerve gas up at ground level. He'd seen Iranian schoolchildren used as human shields for advancing soldiers.
I soon realized that he was carrying around memories that 99.9999% of people couldn't live with. That, in my book, makes him a heroic person.
Naturally, he left Iran as soon as he could.
Later, when I volunteered for Iraq, then for Afghanistan, as a volunteer for flight duty, I sometimes carried an American flag over the armor plate on my chest. But my real armor was for my mind, having taken from a true hero the knowledge that I could easily endure ANYTHING in my little world. And I did, easy-peasy.