If you can't forget, then you really haven't forgiven.
Wasn't it Corrie ten Boom who once remarked, about a particularly vile thing that had been done to her in the past, "I distinctly remember forgetting it."
In a perfect world that would be nice. We don't live in a perfect world. To forgive bad behavior is a great human quality. To forget that bad behavior, is pure stupidity.
As a people, the Jews have been forgiving their enemies for thousands of years. They've been smart not to forget the transgressions made against them.