Where in the world did BUFFY come from?
When BUFFY THE VAMPIRE SLAYER first made itself known to us in the summer of 1992, I was really struck by it. (I confess that I didn't actually watch the movie until many years later: I was still a kid at the time, and the plot of the movie scared me because I actually believed in vampires back then!) The basic premise seemed to me like one of the more original ideas for movies in years. I've since seen the movie three times (four, if you count catching some snippets of it on basic cable one night) and have always wondered from where Joss Whedon got his inspiration for the Buffy character and the world she lived in. Given what I know about Hollywood movies, I think I can make some good guesses.
Casting teenagers in important roles in horror films is a tradition in Hollywood going back at least to the 1950s. Maybe Joss had always been a fan of I WAS A TEENAGE WEREWOLF, or the THRILLER music video, or A NIGHTMARE ON ELM STREET - or even the big cult vampire flick that had preceded this one, THE LOST BOYS.
Then again, since BUFFY is also a comedy, maybe Joss was drawing upon the equally long tradition of movies putting teenagers in mythic or science-fiction situations to get humorous results. I think Walt Disney did it first with such films as THE SHAGGY DOG, THE ABSENT-MINDED PROFESSOR, and THE COMPUTER WORE TENNIS SHOES. More contemporary examples that Joss almost certainly saw would include WEIRD SCIENCE and TEEN WITCH.
And after rewatching the film and then dipping into a bit of British literature and folklore, I think there is a good case for suggesting that BUFFY is a modern-day Arthurian legend! In both we have a kid with an unusual destiny, a supernatural old man, and an iconic bladed weapon.