I'll trust your word over multiple men who fought in the war and experienced it firsthand.

I never asked you to trust my word, I suggested you open a proper book. You might discover that your granddad wasn't the only person who lived through the war and that he might just be biased.

Ok random armchair historian on Reddit.

Unlike you I live in a country that actually lived through the war. If I want to connect with it I can/could talk to my elders, who ALL lived through it, some as combatants, some as civilians. I can also go to my parents' house and look at the spot where 6 of my relatives (and some neighbours) were shot by Germans. My late gran, who died when I was already in my 30s, could roll up her sleeve and show you the numbers tattooed on her forearm. I could also show you the scorch mark in the dining hall from the time when retreating Wehrmacht troops tried to roast whole cow with a flamethrower while they made the women cook for them under threat.

The difference with your granddad, who apparently hated the French till the day he died, is I can do all that and yet tell you that I like and respect Germans an Germany, and that I'm happy that my grandparents could look past recent history and build the EEC with their former foes.