forgiveness

"forgiveness is giving up all hope for a better past"

I read this somewhere - the Internet is rife with bits of wisdom like this, misattributed or not, but this one is so simple, yet so hard to achieve.  Yes, if we let go of the past, we are truly free, for then we have nothing, and having nothing, there is nothing to lose.  And yet how can I give it up?  What to replace it with?  Nothing that can happen in the future can ever make up for what I have lost.  Nothing. I have to replace it with nothing.