My father was an alcoholic. My parents divorced when I was a teenager, and it was a bitter divorce. My mother got custody. My father always paid child support, but he was completely absent from my life. He didn't even acknowledge my high school graduation, and refused to help me go to college so I did it on my own.
As an adult, some of the things he would say would be quite hurtful. For instance, when I phoned to tell him he was going to be a grandfather, he said he wasn't going to be responsible for anything. I wasn't looking for financial support, but my father was not happy at all. I realize now that my phone call had caught him when he was drinking, but at the time I didn't think about it. For the next few years, we would talk over the phone, but sometimes he'd be quite nice and encouraging, but other times (when he was drinking), he would make me feel like a worm. I really hated to phone him, because I had no idea how he'd react.
When my son was very young, my father phoned me and said he'd checked himself into rehab for alcoholism. He told me he did not want his grandson to grow up with an alcoholic grandfather the way I had grown up with an alcoholic father. This eased our relationship. It also made me look at alcohol abuse, and how family members are affected.
A few months later (he was still in rehab), I got another phone call from my father. This time he said he was phoning to apologize for all the hurtful things he'd said and done. He said the rehab had made him realize how hurtful he was to others when he was drinking, especially to me, his daughter. He apologized and said he was going to do better. I should note that he did not ask for forgiveness. Years later, in our conversations about life and things, he mentioned that asking for forgiveness puts the other person in a tough spot.
My father's apology fully healed my heart. Even though he did not ask for forgiveness, I forgave him anyway (and I told him so). My son grew to know his grandfather, and I felt like I finally had a father after all my growing up years without one. Just before he died from lung cancer 20+ years later, my father apologized again, and I said (again) that I'd forgiven him.