Your honesty and self reflection is refreshing, and the situation you describe may be true of many relationships.
Another take, is that your water and my water may be different. Para-conceptualizing Tolstoy, everyone sane is the same, but everyone’s insanity is different. To me, my coparent’s post marriage behaviour is nuts. My behaviour is very different from hers and I have no doubt, based on her continuing posts on FB to ex-mutual friends, that she thinks it is insane or nutty or whatever.
This is completely in addition to people and their values changing in different directions.