I find it easier to forgive when I am reminded of the words, “Forgive us our trespasses, as we forgive those who trespass against us.” That’s one big incentive. I am occasionally in need of forgiveness, too, and I don’t want to leave any obstacles in the path.
That doesn’t mean it has to be the same sin. Forgiveness is a general term, and we shouldn’t think that ours was only a small sin. It depends on him who was offended. I like to clear the deck and start off even again.
As for revenge, that is definitely wrong. If you are a member of Judeo-Christian civilization, don’t even think of it.