Forgiveness is the healing of wounds caused by another. You choose to let go of a past wrong and no longer be hurt by it. Forgiveness is a strong move to make, like turning your shoulders sideways to walk quickly on a crowded sidewalk. It's your move.
I can forgive, but I cannot forget, is only another way of saying, I will not forgive. Forgiveness ought to be like a cancelled note - torn in two, and burned up, so that it never can be shown against one.