Often, you "realize" the stupidity of beliefs that you had been raised to believe only after time has passed.
Even whilst still in - and even though I doubted aspects of the reasoning on the No Blood Transfusion Doctrine - I wouldn't have concluded that the doctrine was "stupid". Let's just say I was in two-minds about it.
Now, with the passage of time, learning about medical physiology and neuroanatomy and becoming more aware of how the organization has used almost anything to legitimate the No Blood doctrine, I see how totally stupid - and dangerous - that doctrine is.
Part of me understands that, for most ex-witnesses, it is a dawning realization; but another part of me is absolutely astonished that I ever fell for this cranky doctrine in the first place.