Forgiveness is key, though not always possible. Forgetting about it is a less significant step.
Ive made poor decisions, who to trust and what to trust them with; my life has been significantly altered for the worse by the hand of others. I swore I'd never forgive, but I had to, for myself, bitterness was making me too cold and cynical.
Each time I felt angry, I let it happen and let it pass, reminding myself that i was forgiving them so that I could move forward. Exhausting, but worth it to eventually have a more balanced perspective.
Four years later, whenever I'm impacted by these alterations I sometimes get angry and have to let it pass, still reminding myself that I choose to forgive for my wellbeing. I choose to have a positive outlook about this, it shifts the focus and responsibility from the wrong doer onto me. I think forgetting about it works in one off or minor situations. Otherwise it should be remembered without bias.