I was born in but from my earliest recollection knew it was just all wrong....
I third that. I can't remember at one point ever really believing even as a young child. It was always a case of, "i'll do this just in case it's all true". Even as a young child i remember questioning the the justice of a God who kills innocent people, or of a God that just sits back while people are suffering. Now that i'm old enough to logically articulate what exactly was wrong with what i "believed", its a great catharsis.
I don't feel brave or amazing, but i don't feel stupid either. Its a mixture between resenting having been brought up in the truth, and pleasure at having discovered that it was a lie, more or less in my early 20s with my whole life ahead of me.
Resenting that i don't have any sort of relationship with my parents because of it, but at the same time wondering what sort of immoral person i would have been had it not been for the protecting influence of the cult.