I'm glad your freind is getting help and hope that your pop has had soem as well.
I understand the not talking thing though.
I haven't told my parents the whole story of my deployments, though my wife is a great listener (when she stops nagging(J/K))
Talking about those things can't always be an interview. Rapid-fire questions make many people who already have difficulty talking about things do not help at all.
By no means go out and try to figure out every little detail. In time, things will be revealed or they were never to be told in the first place.

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