The conscience clause in the middle of the Catechism does allow for SOME disagreement with church teaching, if done after much effort and labor and discussion and reflection and prayer. One might, for example, disagree with the Church on contraception or divorce or capital punishment under such parameters. There is more gray area in the Catechism than one might think.
Why have a catechism, the Ten Commandments, or even a Catholic Church when there are gray areas that one is free to disagree with?
Actually, you were referring to what I believe. But, no matter. As for your current, quite un-Christian insult, I am simply quoting a very conservative priest with whom I had many conversations about the catechism at my conversion. Life is not all black and white. Good day.