Depends on what kind of person you are I guess? It was (and still to this day is) very difficult for me to forgive my father for many of his actions when I was growing up. But, like Patrick, he's a master manipulator so there are times I feel huge sympathy and guilt for the way I treat him and convince myself he's a changed man and that in the eyes of my faith and my family loyalty he deserves my love and respect.
Yet my brother hasn't spoken to him in ten years and says he would dance on his grave. I guess we're all different?!