Don't hate yourself, vets rarely spoke of the war.
In my family, my dad(his brother died in Holland), and 2 uncles fought in WW II. Over the years, even though we spent many weekends together, at the most, and I'm 50, I've heard them talk of it 6-7 times in total. Even if I was asking questions, all I'd get was "not now".....and "now" rarely came!
Your grandpa, had he wanted to share the war with you, would have, they just wouldn't talk about it!......{(shrug) it was their hell, why share it?...I guess}
KC