Many veterans are loath to talk about their service - ask them about it and specifically ask them what their best memory was. We tend to forget that there are some wonderful and amazing memories tied up in all of the stress, craziness, and horror of war.
My grandfathers didn't talk about their service to their kids, but their nosy granddaughter could get a little random info out of them! They were incredibly proud of their service and spend a great deal of time and money supporting their fellow servicemen, but didn't speak about it, so I spent years piecing things together.
Mama Scooterbug's dad was the only one of the boys from his area who survived their European tank service in WWII, and Grandpa Scooterbug got a last minute rescue mission so he wasn't at anchor in Pearl Harbor as scheduled. Decades later he was still haunted by that twist of fate.