I'm glad you posted this. I'm absolutely in favour of reasoned discussion on this matter. A lot of people tend (often without realising this is what they are doing) to view DV survivors in a way that is quite 'othering' - as in, 'not like me'. It's easier to believe that you could leave if you wanted to, that it must be someone's fault, etc. A while ago I heard some people talking about how women who stay are stupid and I said: "Wouldn't it be awful if they weren't stupid? Wouldn't it be awful if they were just like you?"
This topic was already on my mind because, the other day, someone I know expressed concern about a family member who hasn't left their abusive partner. "You can't fathom why they stay, can you?" she asked. That felt really shit, because she was evidently assuming that I didn't have personal experience; you shouldn't really assume that, ever, about anyone, plus it triggered the same feelings of invisibility and aloneness as I had while I was with my ex, who treated me like absolute shit while telling everyone else how badly I treated him. This all came out when he left me.
As I explained to the person above, it's not just Stockholm Syndrome (which you effectively acquire once you are in a relationship). For some of us, the damage was done earlier; you can't assume that everyone else truly understands, deep down, that they do not have to live with abuse, that they are allowed to leave, that it is not their fault. My mother taught me that you do. not. leave. I really believed that I couldn't, because it was so deeply ingrained.
I also didn't really know what was normal and okay, even though I thought I did. Like many children who have grown up in dysfunctional families, I believed that if someone else felt something negative then it must be my fault; I thought I was responsible for keeping everyone else happy. And my mum spent so much time excusing my dad's behaviour: he was just tired, he was just stressed, just let it wash over you, don't antagonise him, that I got used to it. How was I supposed to learn anything different when that was my childhood?
And there can also be a form of dissociation involved: to actually survive in a DV situation, whether it is emotional, physical, sexual, financial, or any combination of the above, you have to hide the truth from yourself or you would go mad. You can't quite see how bad it is while you're in it, so the feelings go in a box. I only learned that I had lived in terror years later, when I started having panic attacks and feeling the feelings I'd put away.
When you're in the cycle of abuse, you do not know your own mind and you can't think straight; even if you start to see sense, your partner will be able to mess with your mind and undo it. The other point to make is that women whose partners are physically violent are in the most danger right after they leave.