It happened to me with Harry Potter. I didn't start reading the books till after the 2nd movie. So I read the 1st and 2nd book the 3rd came out while I was reading the 2nd. I got stuck waiting a long time for the 4th book. It was almost natural for me to watch supernatural. I watched the x files (same writers) and Gilmore Girls (Sammy) so I have pretty much watched it from the first season :).