(At least I cant remember it being put quite so specifically before - tell me if I'm wrong).
You're wrong. JW's have never been allowed to think for themselves. It's always been frowned upon and leads to apostacy. When I left, I told the elders what I had discovered from the Bible regarding false teachings. At that time it was regarding the identity of Abaddon and the celebration of birthdays. The first thing they asked me was if I'd been reading other literature. I told them no, that I had only been reading the Bible. They told me that it was dangerous to do that on my own. I don't think they believed me anyway. This was 16 years ago.
The funny thing is that their own Bible testifies to the fact that Job's children celebrated birthdays, even though they specifically denied it at the time. There are some Bibles that call the celebration that Job's kids had birthdays, which is why they included a denial of that in their teachings. Now I think that they skip over the question about what is in Job and say that birthdays are only mentioned in 2 places and it was unbelievers that held them. Not so. Compare in the NWT Job 1:4 Job 3:1 Ecclesiates 7:1,2