Frankly I think the borderline disordered have a very primitive and efficient defense mechanism that
I had a brief on-and-off relationship with a lady who was previously divorced 3 times by the time she was in her mid thirty's. I had no idea about BPD at the time.  :)uring that 'get to know you' period of the first few dates, I asked her if she lamented the loss of her first love, as many of us do, even if it is only in some abstract romantic form. When I posed the question to her, she looked genuinely perplexed and said no, that when she is done with a relationship she never speaks to him again and never looks back. So I insisted and asked her if she didn't have any real regrets about any past failed romance -especially one of her marriages--, and she actually shrugged her shoulders and said no; she never thinks about them at all.
Not long after that (after our first weekend together) she suddenly and unexpectedly painted me black. We work together which makes everything 10X worse. For several months she would not so much as look at me and the few times we did connect all I could see in her eyes was contempt. A month or so after I stopped trying and just let it go she called me out of the blue one day and her opening line on the phone was "I'm horny". Then I said "you've been a big s#%t to me" and she responded with a very genuine and perplexed "why"?
Like a fool I got involved with her again. The one good thing about being able to speak with her and asked me why she just ended the relationship so harshly. After all we started out as work friends and she could just as easily have asked that we revert back to friends. Instead she treatment me contemptuously. When I asked her why she acted that way, she actually admitted that she 'hated' me during that time period because it was her defense mechanism, because she was getting too attached to me.
Can you imagine liking somebody and very suddenly and profoundly stirs horrible emotions within you, and that fortunate or not, you have this incredible defense mechanism that allows you to take everything ugly you feel inside and deflect it toward another person, and feel genuine disgust and contempt for that other person? It spares them from the pain of instrospection.
Since her 3rd failed marriage, she apparently sticks to extremely superficial and sexual relationships. She told me she never wants to get married again.
This time around I have been fully no-contact with her. Until a few weeks ago she would either not look at me or look at me with a look of anger or contempt. Now all of a sudden when we cross paths she either smiles weakly or seems to have some sort of hurt look on her face. I desperately want to believe it is regret, but even if it is, it doesn't matter. I know that if she were ever to paint me white again, that we would likely cross some threshold beyond her emotional control and she would paint me black again.
:'( Makes me so sad for the people that get tangled up with pwBPD, myself included. That do feel emotions around rejection and abandonment when the pwBPD turn on them so out of the blue. It can be agony when a person really cared a lot for the pwBPD. All around sucks.