Used to work with a Marine sniper who completed his tour of duty and went into teaching. He had a complete nervous breakdown plus his wife left him [no kids]. Was a nice guy when he recovered, but you could just tell there was something a little off about him. He rarely spoke of his deeds while serving, and only felt comfortable opening up to me because I served in the Navy. It's all about PTSD - that shit is real. I can still hear the kid screaming as he burned to death but we couldn't get to him in time due to an explosion. Pretty intense stuff.