Mine happened to me when I was conducting a Bible Study with a youth in the congregation. He was 15. We were studying a chapter discussing how we (as JWs) know the Bible is from God and not men.
He asked a simple question, one that I had heard a million times before, "How do we know that these men wrote what God told them to write, not their own ideas?"
Instantly my training kicked in and I directed him to 2 Tim 3:16. And while he was reading it, it dawned on me. How can I use the fact the Bible claims it is inspired for proof of inspiration? I will never forget that moment. On my way home the question haunted me until I realized the fallacy of JW logic. The next wave instantly hit me like a sucker punch; if they Society has this wrong, what else have they missed?
Within a couple months, I stopped going out in service and managed to find ways to miss almost every meeting. A couple years later, deep into my slow fade, I stopped altogether.
A matrix moment, indeed.