Lots and lots of cumulative stuff. The "generation" change of '95 really pissed me off, although it took me a while to realize how much. I remember having a sit-down with the C.O. several months after I had stepped down as an elder. I flat out told him that I doubted that the "slave" could be trusted as leaders of our faith, because they waited until it was painfully obvious to anyone who was paying attention that the generation was passing away before they suddenly got "new light". That's not leadership. I remember saying something about the emperor's new clothes, and that everyone could see the man was naked. The only person who was willing to speak up about it was a kid, and in the real story, they probably just killed the kid for saying the truth.
I answered the door to a couple of Mormons and decided to witness to them a bit. They were the first to tell me that 607 was NOT the year of Babylon's fall and Jewish release. I just knew they were wrong, but my uncle, who was a highly-respected elder told me that the secular date didn't agree with the JW date. That shook me pretty hard.
Honestly, I was a terrible student. I barely read the literature unless I had to conduct a meeting. I think if I had been paying attention and actually reading the crap, I would have seen them for what they were earlier. It took a couple of years of seeing a psychologist to deal with my depression before I could actually hear myself saying that I didn't believe any of it, and that I needed to get out of my awful marriage. I separated, moved to the city, attempted a fade (before I even knew that term), but ultimately decided that I was tired of lying about who I was. I asked my wife for a divorce and told her she had grounds to remarry. I never answered any calls from the elders, and was eventually read out at the meeting (at my old congregation, no less) as no longer being a JW.
I no longer have my parents or my children in my life. It hurts, but it was worth it.