Well, a Narnian is a person who lives in Narnia, obviously! And a Narnian fan is someone who is a fan of Narnia, obviously. But WHY?
A real, true Narnian will live to protect Narnia. He or she would believe in Aslan, not some Telsh idol or whatever. No matter what kin, a Narnian is a Narnian when he or she LOVES Aslan, LOVES Narnia. Think of that. Love. Know. LOVE!
And to talk about a Narnian fan.... that person at least tries to be a Narnian himself. To love what a Narnian loves. To know what a Narnian knows. But that is when you go really deep. I might not be that rooted into Narnia! :D But if you are are, try Wikihow!
And, not THAT stupid or retarded you may be, but do you know this? :P