The first time was right after I got baptized. It was at a district assembly and I was riding on a school bus full of JWs. As we were leaving there was a group of people waving literature and trying to get the bus to stop. The driver stopped out of curiosity to see what they were doing. I reached out through the window of the bus as the group was eager to hand me what appeared to be a Watchtower. Upon closer look at the look alike tract I saw that the title was "Not the Watchtower". It was full of quotations from the real Watchtower heavily underlined to emphasize the point. I didn't really read it but it was my first experience with anti-cult evangelicals who used to go to our assemblies.
The passengers quickly figured out that it was apostate material and were excitedly urging me not to read it.
Sometime years later I went to a 'Christian' bookstore and bought William Schnell's 30 Years a Watchtower Slave. I remember being so afraid of it that I ripped off the front covers and hid it even though I was living with my mother who was not a JW. I wasn't too impressed by that book but it was my first careful look inside of the "opposition".