The average age of the Vietnam combat soldier was 19. Paul Hardcastle taught me this and I have never forgotten it.
That's a myth.
Myth: The common belief is the average age of an infantryman fighting in Vietnam was 19.
Fact: Assuming KIAs accurately represented age groups serving in Vietnam, the average age of an infantryman (MOS 11B) serving in Vietnam to be 19 years old is a myth, it is actually 22. None of the enlisted grades have an average age of less than 20.