Face of an Arsehole

I was reading some passage in my book about gene's being passed down a line of logic so if you look like your father and your father looks like his father and his father resembles his father then you resemble your great grandfather. You see it all the time in cartoons and movies and shit were the same actor plays the ancestor when they travel back in time.
I have been told since I was young that I bear a striking resemblence to my maternal grandfather, I just realised I can't remember his name. Anyway this was great gave me a feeling of connectedness and my grandfather was described as quite the dashing young man in his time.
To me he was a fun, warm, active, wrinkly bald old man with green tattoos from war and a malaria yellow complexion curtesy of WWII.
At some point though the other half of the picture comes out, that he was a drunk irresoponsible arsehole that dished out a few love taps in his time.
I've found this hard to take because it's totally against my values and nature. I was a teato before I found this shit out, had a brief stint at pacifism (provoking more violence amongst my friends than previously) and was stingy with the coin.
I don't like sharing a face with this man. I remember being angry with mum when she told me of the darker side for 'ruining a hero' but he wasn't and I got angry at the wrong person. He was a great grandpa and otherwise a fucking arsehole.
Point of the story I feel sorry for anyone who bears a striking resemblance to Hitler they have bigger issues than me.