That my dad cared about or respected me. After a family dinner, my wife asked me if he always talked about me like that and it just kind of clicked. Things like telling my kid, "If you play too many video games, they'll melt your brain like your dad" or "why would anyone pay you that much" when I told them that I broke a six figure salary. She made me realize that this wasn't normal and I didn't have to sit there and listen to it just because of who he is.
I haven't spoken to him or really any of my side of the family in almost two years now. Good riddance.
Not sure if forgiveness is the way to go. At least, I think that forgiveness is important but I think there needs to be some understanding and respect from the parent towards their child too. Without that, forgiveness just puts the child in an unnecessarily vulnerable position.
My advice is to try therapy, if you want to get back in touch with your parents at all