I was once with someone and they knew me (and my health conditions) better than anyone else did - but they didn't want to know me, any more.
Once, after a bad fight, I went into the kitchen to do the dishes and I collapsed, hit my head and fell unconscious to the floor (which wasn't unusual and is a common symptom of my disability). They walked in and ignored everything they knew about me and my disability and accused me of "taking something", of trying to manipulate them by trying to hurt myself - it was then that I knew that I didn't know me at all.
