We often say"Forgive and Forget." That's the correct sequence IMHO. If you want to forget someone or some unpleasant event, you must first forgive. Forgiveness is the precursor to Forgetting. If you don't forgive, you'll never forget, and that someone or that unpleasant event will stay with you, carved inside your heart and deep in your mind. Like a magma chamber of a volcano, you will then embody the hot burning lava of hate and volcanic ashes of bad memories. So to move on with life, you ought to learn to forgive, first and foremost, even the worst people round you. The stream of life would then flow smoothly and seamlessly - onwards and upwards.
Deodatta V. Shenai-Khatkhate