Do you know what the term "fannish" means? How about "filk" or "fen"? Or "Twonk's Disease"? If not, there's a good chance you're a mundane, which is to say you're not a hardcore SF fan. For you, David G. Hartwell--one of the field's finest editors and most stalwart champions--has written
Age of Wonders, a book about the inner workings of the SF cognoscenti. It is an intriguing look into the rabid subculture spawned by science fiction that also offers insights into why some people give up reading SF in their teens, while for others it becomes a lifelong passion.