A few times you have mentioned this, and I always remember it, my newest next-door neighbor, is a Marine, served in Vietnam in 1966, each year holds significance. We are decent neighbors, but one more than one occasion he has told me that even his family does not know what he did, and what he lives with each day.
He tells me small stories, and I tell him about someone I knew for many years who was a machine gunner on a helicopter 1970-71. Never give this man a Jack Daniels and ask him about Vietnam. I told my neighbor that he was crazy, my neighbor would remind me that he was already crazy before he went to Vietnam. Vietnam just allowed him to fulfill his ability to be crazy. He was just crazy with a machine gun.