Hi there, I can only answer this based on how it feels for me.
Forgiveness is the acceptance of anothers words or deeds that have caused us personal pain hurt etc. In order to make that forgiveness meaningful it has to be heartfelt and sincere. This doesn't mean we forget what someone else has done, or that we have to forget, however by forgiving we are dealing with the emotions that they made us feel, we are bringing something positive to negative feelings. Some people can calmly forgive others by uttering the words, 'I forgive you' however they may not have felt hurt at a deep level. The deeper we feel anothers hurt the more sincere our forgiveness is. We may never erase totally their actions from our minds, but forgiveness will work towards neutralising the emotions caused from the hurt. So I don't believe that we need to forget so long as the forgiveness is heartfelt, and that by forgiving someone we are making a decision to accept and let lie, those actions, or words of another, and to give ourselves peace and the opportunities to restore the status quo with that person. Hope this helps.
Love and Light Topaz x