I had a similar experience to OP. But the catalyst for me was the Mountain Meadows Massacre[1] which I was completely oblivious to until my mid-20s. It was quite a shock to learn that the church (which I thought was "God's perfect organization") had such an ugly past. The most disturbing part was how much effort the church put to hide and scrub events like this from its members and the rest of the world.
[1] https://en.wikipedia.org/wiki/Mountain_Meadows_Massacre