I do have a genuine question about this particular area.
One of my friends was married to a horrific, narcissistic abuser. She's now happily remarried to a total sweetheart. But, she constantly talks about her ex-husband. She actually went out of her way to talk to his new girlfriend and warn her about his abusive, narc behavior but the girlfriend didn't listen. That happened almost 2 years ago and she is STILL talking about it and STILL trying to convince the girlfriend to leave him.
It makes me wonder whether there is some sort of traumatized mentalilty that remains after you leave a relationship like that that makes you a little more... obsessive?