This may seem like basic common sense, but one interesting (and kind of terrifying) thing I recently read was that some individuals who grew up in an emotionally abusive environment find that their anxiety level actually decreases in the presence of those who are mean or overly critical of them because it's familiar. Their nervous systems are hard wired to react to that kind of treatment as "normal" in the sense that it knows what to do with it--what defense mechanisms to employ when, etc.
Meanwhile, kinder, more peaceful, and healthier relationships are quite a dramatic adjustment, and ironically feel less predictable because of all the threats that are absent and never materialize. It feels suspicious or too good to be true, which in turn ratchets up hypervigilance and hyper-arousal. Instead of knowing what BS is coming because it always does, there's the nebulous sense that the other shoe is just waiting to drop. Safety and respect can feel the most unsafe for a while, because as far as the traumatized nervous system is concerned, those things don't exist, or if they do in any form, there must be a million unseen strings attached.
This is part of what traps a lot of people in abusive relationships, consistently draws them to want to please assholes, or keeps them moving from one unhealthy environment to the next--a highly toxic comfort of familiarity where being on the receiving end of cruelty feels like "home".
