[T-Bird45]

They did it, forgot it and just got on living the rest of their lives.

For some portion of them, that was the case. For others, pretending to forget it only led to larger problems with "living" the rest of their lives. As your father pointed out with his question to you, even "good wars" are horrible in the damage done to the human psyche. Some handle it better than others. My father was one who did not handle it well, dying of alcoholism at age 53 when I was a senior in high school.

[oh8eleven]

My father was one who did not handle it well
I'm sorry to hear that. Back in the day was much different - the WWII vets were essentially told to go talk to a priest about their problems or just suck it up.
Today, vets who cut themselves shaving while stationed in Hawaii are claiming PTSD.