My good friend and neighbor of almost 40 years did 4 tours in Viet Nam serving in the Marine Corps. Only towards the end of his life did he ever start talking about his experience. A lot of times he would only recount the funny things, but eventually would talk of the bad. He had nightmares for years. Sometimes he would camo up, grab a weapon and go sit in his tree line in the back yard for hours at a time. He told me once that is where he felt safe and "at home".