It wasn't until my wife and I visited Hawaii and Pearl Harbor on our honeymoon that it really clicked for me that WWII vets were young guys at the time, in fact, the same age as I was while visiting.
Up until then I kinda always thought of them as old grey-haired guys, I mean, I logically knew that they weren't elderly during The War but it wasn't until that visit that it really hit home how young they really were.
Was a very somber feeling.