This is what comes to mind:
"My religion is so important to me that (a) I had no idea about one of its most controverisal but definitive doctrines, and (b) when I discovered that I had inadvertantly violated that doctrine I decided it was best to leave the Church."
I think out "teachers and pastors" bear some of the blame for this. Has anybody ever, EVER heard a substantive sermon on Catholic sexual ethics? Even in passing? I figure I've got to about 5,000 Masses in my lifetime. I've heard NOTHING about John Paul II's magnificent "Theology of the Body," about 3 sermons which even
mentioned abortion
in passing (like a sentence or two: no real development or in-depth explanation), zero mention of contraception, and of course zero mention of IVF.
The level of knowledge of the majority of Catholic laity would have to rise to reach the level of abysmal. And that's a commentary on the level of teaching and preaching.