How Can We Ever Forget?

My life after the betrayal has been, what should I call it, "disturbed". I am not the kind to easily forget even though I easily forgive. I hate it when I wake up in the morning and the first thing that came to my mind is the bitch. I hate being the person who can't easily forget.
But one dear friend, another Cheated Wife, wrote this to me:
"I don't forget either. Because I believe that forgetting is not something one SHOULD do. Or should TRY to do. It's a natural process that happens when you are busy doing other things. And when 'other things' are done, one comes back to the memory... painful or otherwise.
However, I do forgive myself for being UNforgetful. I forgive myself for being human and for still hurting. I'm taking my own sweet time to heal.
I really think we should NOT forget. If we forget, we might make the same mistake - again. We might be betrayed - again. What happened was a lesson. So we learned. We don't forget".
We forgive but don't forget. Perhaps that's the curse of being the Cheated Wife.