Doctor Who and the Fandom of Fear describes Doctor Who fandom, but it could just as easily describe any number of geeky obsessions (D&D, comics, Star Wars, etc.):
And nostalgia, apparently, is a central part of the show’s appeal. “It’s an odd television program in that it’s very rare for someone to become a Doctor Who fan later in their life,” says Alan McKee, a senior lecturer in media studies at the University of Queensland who studies Doctor Who fandom (and is himself a self-described “Doctor Who obsessive”). A fan can be any age, he adds, “but they always start off younger. From the time its first audience started growing up, the history of Doctor Who has been fans condemning the program for not giving them what they want anymore. And of course what they want is the same experience they had as a child.” The flipside would be viewers like me, who gave up on the show because we wished it would grow up a bit — and who briefly came back when the program showed signs of greater depth.