Sarafina7 wrote:
Something that's popular i.e Harry Potter.
If you know a lot about it, then you're just considered a really good fan.
I'm not sure. Even if it's popular, you can still - outside of online fan communities - be viewed as 'weird' for knowing too much about it or discussing it too much, even by people who actually like it.
When the Lord of the Rings movies were coming out, they were of course very popular and many people I spoke to had seen them. Yet even those who enjoyed them still seemed to think it very peculiar that I knew so much about the characters, the cast*, etc., and very peculiar that I should want to or be able to analyze them in detail.
*Knowing a lot about an actor - i.e., more than you can find out from a gossip rag - also seems to be seen as weird, and the more obscure the actor, the weirder it is that you know a lot about them.