...I feel so much better now.
It's all gone, like someone stopped pounding me in the head with a hammer. I didn't even know the hammer was there. Why did I let someone pound me in a hammer all that time? What in hell was I thinking? Why did I think any of that made sense?
Once you're out of the system, it makes no sense at all. None of the carrots they dangled before you mean anything, and you start to truly comprehend just how much stress you were under. You see things you never would have believed while you were in the system. And the relief is greater than you ever could have imagined while you were enmeshed.
From How to keep someone with you forever by Issendai
The worst part of these systems, I think, is that you can fall into them over and over again. It's the same reason you don't remember how much falling and breaking your arm hurt when you were 8. You'd never get on a bike again if you did.