For me it was a long process. I was asssociated with the Witnesses since about age 3 and through the years I had a number of times where I'd run into one pesky doubt or another(though not as many as I probably should have had).
In my very early 20s I was having a discussion with a friend about evolution vs creation and it hit me that I just didnt believe what I was saying. I realized right then that there was no god and I was living a huge lie. All the little warning signs hit all at once and I really had a moment of clarity..... This was immediately followed by a wave of panic that lasted for the next few months while I re-brainwashed myself.
A few years later I found myself in a zealous frenzy. I decided to read all the publications, to read the bible cover to cover, etc, etc. The only problem was that the more I poured into it, the more doubts I had. I found the circular logic and stupidity in the mags and books absolutely horrible. I couldnt seriously deal with the bible because I found so many holes in it. I started to have fun at the meetings by making comments that had double meanings so I had something to keep me from going totally insane.
Unfortunately it came nearly to that. I got to the point of a nervous breakdown, that is the inability to make a decision at all. I knew I had to leave, but the pressure was just too much and it finally came to a head one morning while I was at work.
I had to leave the office and I did the only thing I could think of.. I called my oldest friend and spilled my guts. While that helped, it had a cost. He hasnt spoken to me since. While on the one hand Im appreciative that he was there to listen, on the other hand... Fuck him. All that really did was confirm that I really didnt have many true friends among Jehoovers happy people and I knew that there would be more losses to follow and there have been. Though I'm only inactive and not DF or DA, I am openly shunned by everyone I used to know. There are 3-4 people that I call friends among the witnesses that still talk to me....... Though Im certain they wont be far behind the rest if Im pushed to be more vocal about my situation.
My salvation from the insanity of that cult was simply my own mind. I just had to convince myself that I was allowed to use it.
Praise Science! Im Saved!