Catholic Inquisition = proof that it's a false religion
Failed JW predictions = proof that the light gets brighter
Are the JW's I know the only ones who poo poo older articles and say that thinking isn't up to date anymore, that new thinking has superceded those new articles?
It's called cognitive dissonance. From a psychological viewpoint, we must align our thoughts with our actions. Therefore, we either change our ways when we realize our thoughts are not in harmony with our actions or we explain them away or, in extreme cases, outright deny that the conflict exists.
For instance, let's say I'm a wealthy warehouse owner and I get an offer to purchase my plant. I know that if I sell, I could make a nice sum of money, but the new owner intends to shut the plant down and lay off all the workers. At the same time, I consider myself to be a good-hearted righteous Christian. So there are basically two routes I could take: (1) I refuse to sell the plant and save my employee's jobs or (2) sell the plant and justify my behavior, perhaps by saying that I have to act in the best interests of the business or something along those lines. The conflict between my own perception of myself and my actions that are out of harmony with that perception need to be remedied somehow.
That's what happens with Witnesses. Upon presenting evidence that their thoughts about themselves with respect to being followers of the one, true religions are incorrect, they will try to explain away the evidence so that they can hold on to their views. The mind wants to harmonize beliefs and the evidence you're presented with. So JWs will often minimize the importance of some piece of evidence that demonstrates that the Watchtower does not teach the truth, or in some cases, they will outright lie and say dismiss the evidence as being fabricated (evil apostates!).
It's just how the mind works. It's like the guy who always wanted a stable family life, but deep down knows his wife is cheating on him, yet refuses to believe it. When his best friend confronts him with hard evidence of this, the guy punches his buddy in his face instead of accepting the truth of the matter. Eventually, he will either have to change his thoughts (accept that he's married a two-timer) or continue to dismiss all evidence that points to this conclusion.