I often say, the forget aspect of "forgive and forget" does not necessarily mean we have to erase the memory because it is impossible. It is about letting go of how much it hurts and denying our minds the privilege to fixate on the pain.

When we truly forgive someone, the thought of the incident will no longer bother us and does not mean the incident has been erased from our brains, we have just manage to let go at that moment, to release us from the shackles of the painful memory.