conscious or aware of something
[with infinitive] formal inclined or willing to do something
That's what makes us stay. When we are getting hurt, bearing in mind we can only get hurt more. But we stay anyway.
That disparity can lead to some serious consequences. For emotional abusers this is a perfect base, an invitation to create/join this cycle. Being abused in a relationship of any kind might often leave you hurt (being the victim) and feeling guilty for it at the same time (guilt pushed onto you by the abuser - comforting for himself to be rid of it, ensuring you will keep quiet about it, and making you more obedient and even apologetic often).
In a relationship, there might be a lot of feelings leading a person to feel that way. But mostly feelings for another person are the catalyst. Accepting that someone who we sacrifice ourselves for and go through days miserable, with the feeling of worthlessness does not love us is sometimes not a choice to make ourselves feel better. Sometimes we understand that someone who acts this way cannot possibly love us while wanting us to suffer this much. We can see it in others easily and see it for what it is - abuse. And we can usually see it in ourselves as well. There are doubts. But in the end admitting it out loud is too much for a mind to bear so we believe the lie instead. Not a conscious choice. Not a good one. On top of our previous doubts it just causes more guilt. But on the other hand we have a tougher one. One that leaves us feeling unloved, lonely, still guilty, stupid for getting lied to like this, and just as worthless as in the first case.
There is no easy way out of it.