IMHO, forgiveness is really at its heart about ourselves, not the other person. And I think a lot of it lies within our values and within our individual situations. And in what we do next, how we make amends. Also in whether we manage to use and identify our strengths to make ourselves whole again.
My H has said many times he will never truly forgive himself because he does not think he should be forgiven. I suspect that will be true for a long time to come. There is big work for him to do, I think, before he gets there.
One thing I've struggled with is why we choose to continue on paths that we feel this way about. I don't say this to judge anyone... I say it because I personally can't do it.
I've learned this from experience. My C once said to me that feelings of guilt from things we have done serve a very necessary purpose-- they define our conscience for us and show us where our behavior needs to change. So we can change the behavior and let the guilt dissipate with our healing and amends (we're not doing that anymore, so there is no basis for continued guilt)... or keep doing the same thing and be wound up in pseudo-guilt or self pity.
This helped a lot when I was trying to change my own behaviors.
Joanne, I'm glad you found that bit about pain useful. It is probably the key thing DBing has taught me.
A lot of times this is us not dealing with the vestiges of pain, not taking control of our life, making excuses, and not taking a good look at our values or the meat of DB principles. Big tunnel, no cheese.
Joanne, do we have the same OW? I've come to have compassion for the pain she must have been in to be that destructive and hurtful. I do know she has issues with depression and previous negative R experiences, that in her words she "wants a partner so bad". That said, even if I do get to a forgiveness point with her (mostly I choose not to think about her much), I know that I don't respect her, that she's still doing it, and that I'm having a hard time respecting my H's behavior while he's in that R (there are factors for this beyond the fact that this A severely damaged our M).
I think we keep DBing in the sense that it becomes a way of life. Other than that, I have no answers.