Hmm, my grandchildren genuinely believed I could do magic, but were increasingly dubious from about 5 years old on. Children are innately trusting, it’s probably a useful evolved trait, give how long humans take to reach adulthood, but I don’t think all children are gullible.
The really cool thing is we can continue to learn throughout our lives, if were willing to keep an open mind.
I’m lucky to have avoided any form of catholic teaching. I’m usually appalled when adults tell me some of the things taught and done to them as part of that particular superstition’s indoctrination.