Knowing the origin of a pop culture franchise probably won't change the way you feel about the franchise, but if you're as obsessive about your favorite stories as I am then you'll probably do some digging.
Researching will uncover simple roots for many franchises, but then there are franchises like Predator, Super Mario Bros., A Nightmare On Elm Street and Gilligan's Island that have some pretty unusual origin stories.
The 'shrooms that make Mario grow up big and strong in Super Mario Bros. look just like amanita muscaria, the hallucinogenic mushroom, so the game could be seen as one big 'shroom trip. Gilligan's Island also has a fairly simple origin- the islanders represent the seven deadly sins.
A Nightmare On Elm Street started with a news story about a deadly nightmare killing young men in southeast Asia during the 1970s and 80s.
Wes Craven read a news story about a bunch of young men who died of SUDS (sudden unexpected death syndrome) in their sleep, combined that with a bully from his childhood and Freddy Krueger was born.
And last but certainly not least there's Predator- the Rocky sequel we never knew we wanted until we saw it in theaters. Predator started as a running joke in Hollywood that said Rocky would have to fight an alien in Rocky V to top Rocky IV.