So as I sit there with my friends, or talk to them on the phone, and hear myself saying "we do not believe in Birthdays because someone got their head cut off" or "we do not go to college because the world is ending soon." I might feel a little odd now, realizing that was something I used to accept, but I have to remind myself many times. "It did not sound odd then" and that was because I just did not know anything else, and I was just doing things I would learn from later.
The reason it seems so odd, imho, is that those were not the real reasons we believed those things. We didn't believe that birthdays were wrong because some people got beheaded; not really. We believed it because we had unquestionably accepted an organization as being God's sole representative on earth, and that organization told us it was so. They could have told us that birthdays are wrong because the moon is made of green cheese, and we would have bought it.
Thw Watchtower doesn't have to convince us of a lot of doctrines to get our subservience, only one. If they can convince us that they, and they alone, speak for God, they've got us. Once we believe that, all else follows, no matter how foolish it seems to people on the outside.
In a way, it's a house of cards for them, though. Once we see "the man behind the curtain," so to speak, the whole thing falls apart just as quickly as it was accepted. And going back (at least while retaining a shred of integrity and self-esteem) becomes impossible.