My grandfather was a tank driver with the 2nd platoon, B Company, 745th Tank Battalion. His company was the very first unit to get American tanks on Omaha beach on D-Day in support of the 1st ID. According to the reports, they started the landing with 12 tanks, and only 2 survived. He later won a bronze star when 8 of his fellow soldiers were captured by a German infantry squad, and my grandfather rescued them, killing 6 German soldiers in the process.
We didn't know a thing about any of this until after he died. He never spoke a word about his awards, or the battles, or the things he'd done or seen. I found the bronze star in his personal stuff after his death, and that got me interested in looking into the rest of his history.
You want to know what he did talk about, though? He told us about the concentration camps, and what one group of people with guns, could do to another group of people who didn't have any guns. To him, that was the most important lesson of the war, and the one thing he wanted all of us to remember.