So uhh... we broke up (divorced soon after) 9 months ago. My ESTJ ex keeps messaging me from time to time, saying things like we shouldn't have divorced, that the time we spent apart made him realize that I am the best woman he met and so on. I politely explained every time that I have moved on and have no desire to be with him again, along with 5452415 reasons why it wouldn't work for the second time.
I was so happy when I found out via friend that my ex started dating someone. Yet when he messages me (about every 2-3 weeks) and he talks about her, he keeps complaining how she's not good enough, that she irritates him with XYZ and subtly compares her with me. I always tell him things like the thing that he finds irritating is actually a trait he might enjoy (such as disorganized = carefree, he would definitely benefit from learning to be more carefree), that he should accept her the way she is and focus on the good. I have no reason to put her down, I always encourage him to stay with her, to work on making the relationship work and be happy (with someone other than me).
Why is he like this? Why can't he let go of the past? Is there anything I can do to help him move on?