Family secrets

Yesterday, we learned that my grandfather was not my mother's father. We will never know who her father was. I wonder how my mom would've handled that... I can imagine her grieving the loss of her father and then suddenly finding out he wasn't her father... She'd be so confused...
He wasn't a good man... Which is part of the reason this is so confusing. He molested children, and hit on my mother a few times... I remember her telling me how horrified she was at the things he said... Something like, if you weren't my daughter, we could have a lot of fun. She was in her thirties and having lunch with him. He was married, although obviously, this was creepy all on its own...
I can't believe the bastard lived to his 70s.