I love those types of therapy moments, bellsring.
Pixie, by the way, I spent aaaaaages googling and researching and wanting to understand every detail of why stbxh is the way he is.
At some point in this process, I looked at myself and thought: "hang on, shouldn't I be spending all this time and energy focusing on understanding and healing myself?"
So despite what I said to you above, I think that researching the abusive mentality can be a helpful part of the process, if the result is that it helps us understand that, yes, it was abuse, and no, it wasn't our fault. The difficulty is that we are so used to spending all our time focusing on others and wanting to help/cure them, that the intensive research into abusers' mentality can sometimes stem from us still wanting to "save" and "help" them, and divert precious resources we should be aiming at ourselves, for once.
Acceptance is the goal. Thorough understanding may be a path to acceptance. As may be just saying : "fuck it, he really isn't worth my time anymore."
Have any of you noticed that despite its title, "Why does he do that?" doesn't actually answer the question? Instead the book is just saying in big blaring letters: "See that? It's abuse. It's not you, it's him."
It really answers the question: "What is he doing?", not "Why does he do that?", and I think that's the more important question.