Had I not been introduced to and subsequently studied detachment during and since my divorce, I would likely be in a similar place. It's an ongoing practice as memories come flooding back with or without provocation still, 18 months after finalization. I was open to the lesson and for that I am extraordinarily grateful.
No one likes being the one left behind in the dust....when your spouse dumps you for reasons you may not even be able to comprehend, it seems to help some of them to start "The List". As time goes on, the list becomes longer and longer until one day a therapist (or perhaps a good friend) points out to them that if all of those grievances are valid, then perhaps he or she dodged a bullet.
It was only recently that I realized that I was still holding on to my painful memories (after 8 years!!) and decided that it was long enough (way tooooo long enough). I guess each person has their own timetable. Moving on is always a great option but for some people sadly,(I include myself in that group; 8 years being evidence of that) it is more difficult. Life is way too short!