It's not that I misunderstand, though I freely admit that even when I was raised Catholic, and going through the confirmation process and stuff, I never fully understood it.
What I meant was not having the ability to really make your own choices. and I'm speaking about the "Devout" Catholics, not just anyone who goes to mass in a church that starts with St. something.
No options on conception/birth control. No divorce. No option to support a gay/lesbian friends choices.
Those are my biggest turn-offs for the Catholic faith, and sometimes I actually feel sorry for people who never really get to have their own opinions on some of these things, lest they be ex-communicated.
Note: Please don't read this as me attacking your faith or religious choices, this is simply me explaining why I feel as I do about Catholicism.