I think I'm reading different definitions of what forgiveness means.
My father was a terrifying, violent asshole when I was a child. I hated him for years, long after he died when I was 14. About 10 years ago, I grew in my perspective of his situation - he was terrified, lonely, a bitter atheist, prescription-drug-abusing, always worried about money, treated coldly by his own mother (probably for good reason), and a sex-obsessed misogynist with no male friends. If I had set myself up in that kind of situation, I would have been a raging, furious, uncontrollable asshole too.
When I got to that understanding, my hatred of him evaporated, and was replaced by a pity and even a compassion. It doesn't mean he didn't make my childhood a nightmare, and it sure doesn't mean I'm not still living with the consequences to this day, BUT it does mean that I'm not poisoned by all that ill-feeling toward him putrifying inside of me anymore. And most of the PTSD effects seem to have melted away (I think). It was definitely a miracle to have that shift. And after a few years, I now see that that's a kind of forgiveness.
My mother was an active alcoholic while I was growing up, but mostly my ally, much, much better than my father. But forgiveness for all her neglect of me didn't come til I myself became a mother. As most of you know, I make a really big deal out of being as good a mother to my daughter as I can be. And one day it dawned on me, that even being a MEDIOCRE mother must have been a huge amount of effort for my own mother - she's basically very self-absorbed, and back when I was growing up she was a single mother, working full time during the day, and drinking, smoking and who knows what many evenings. Another thing that has helped me release my hostility toward her is standing back, now, as an adult, and seeing how often she is inconsiderate to others. For most of my life I took very personally how she treated me. Come to realize, that's the way she IS. Yeah, it hurts to have a mommy like that, but Jesus H., it's liberating to realize it's not about ME. Ya know? I think I'm only about halfway toward forgiveness with her, or maybe even less, but what relief I've had makes me want more.
Finally, there's this great quote, I don't know where it's from, "Resentment is like taking poison and expecting the OTHER person to die." That fits exactly for me.