I just worked out that a big turning point for me was reading George Orwell! He writes about people who stubbornly keep bludgeoning themselves with their pet cause; holding on to their beliefs in spite of the consequences to their life.
Themes from 1984 come up here regularly; 'doublethink' - the ability to suppress a thought that contrasts to what is acceptable to the ruling authority by turning it over and just accepting that their version of the truth is the truth. When his characters were doing that, sirens were going off in my head. The 'Ministry of Truth' is the government organisation that destroys all documented evidence that an historical event ever happened, and replaces it with their own version of history. We see a lot of that from WBTS, my favourite example being that the current CD 'comprehensive library' of WBTS publications doesn't contain the older publications that they're too embarassed to admit was doctrine only half a century ago.
The clincher was A Clergymans Daughter: Dorothy Hare lives with her father, the local priest, and has to work out what her life is going to be if she spends it presenting a faith she doesn't have. When I read that story I was right at the point of deciding who I should be: Dorothy, or take the chance on what happened outside the bounds of what I was comfortable with. I know I made the right choice, and if I had to do it again, I'd do it twenty years earlier.
Those stories gave me the perspective I needed; looking back, there was no alternative input into my thought process to what was being churned out of the WBTS machine. It was a jolt, but it paid off. Worth a try...