Borderlines make you feel so loved and needed at first that it is very seductive. And then, eventually, when they turn on the "hate," it is a real mind f*ck. And we can't "love" or "understand" them out of it.
Going dark won't help because it doesn't even occur to them to miss us; they just get colder. But, sticking around only fuels the drama that they crave, so we're screwed either way. Again, the "no win, no solution, no way out."
I have to keep reminding myself that I was nothing more than an object to be discarded, and then they are on to their next "soulmate."
I know how much it hurts to realize that in these cases, nothing is "real."