I have learned to forgive just recently actually. Recently being the last five or so years.
I forgave my ex-spouse for things that I once considered unforgivable. I will not forget though. That would, in my opinion, make me a fool. I forgave my father. I forgave many people of things that did nothing other then consume energy and waist my life hanging on to. What I learned from it was it only made a difference in my life, one way or the other.
Regardless of my forgiving or not forgiving, makes no difference in the life of the person or persons who hurt me. However, it does make all the difference in the world regarding the quality of my life and my relationships with those who are important to me and who are a part of my life now. So by not forgiving, I am cheating myself and those I love. And as for many of those arsholes that hurt me, they get theirs in the end.
I now have friends and loved ones who respect me but those who tormented me or robbed me have empty worthless lives with nothing to comfort them. They are sad little people and I have no reason to carry them on my back for the rest of my life.