It's amazing the amount of Stephen King movies I saw before I even read a single word of his prose, and even more amazing to me that I only realized just how much of it was his stuff when I discovered the internets. I watched Stand By Me whenever it came on television,and I practically wore out my VHS copy of The Shawshank Redemption before I finally got a hold of the DVD version. I've never liked horror or scary movies of any kind -- they just don't do anything for me*, so I've never really felt the need to subject myself to them. And Stephen King is known for his horror (which is something he talks about in the afterword to this book in a very interesting fashion, actually).
*There have been a couple of exceptions over the years. If a story's got something else going for it that can keep my mind interested and distract me from whatever nasty thing is going on, like with Cabin in the Woods and the Scream series, or if one of my favorite actors is in it, then I'll give in and watch it. That last one can backfire, though. I sat through the entirety of White Noise 2: The Light for Nathan Fillion and Katee Sackhoff and by the end I was just like, you guys are so pretty but ARE YOU SERIOUS RIGHT NOW.
Anyway, to the point. I had NO IDEA that both of those movies were Stephen King creations, and when I found out it was like [head explodes]. Since then, I've found that I enjoy King's non-horror writing quite a bit. It's got just the right amount of freaky to it without descending into madness, and some of it (like Eyes of the Dragon) is just downright charming. This collection of novellas was King's first foray into non-horror, and it's pretty great. "Rita Hayworth and The Shawshank Redemption" was a nice read (although, as the movie is pretty faithful to the book, I've gotta confess that I prefer the movie due to the book's distinct lack of Morgan Freeman). "The Body" (which became Stand By Me) is a haunting story of four boys coming of age in the 60s when they go looking for a dead body in the woods. The story has a slightly different emphasis on some themes the film couldn't fully flesh out, but I enjoy both versions equally. I've never seen Apt Pupil, but I might have to now that I've read the novella. It features an extremely creepy relationship between a young man and an old NAZI war criminal (but not sex creepy . . . way worse, actually). That story more than any other in the collection proves that King doesn't need the trappings of the horror genre to tell you something terrifying. The last story in the collection is "The Breathing Method," which does slip a little into the supernatural, but it's actually kind of a sweet story (this is a weird thing to say, if you know the plot, but I feel like it's accurate).
I usually tend to stay away from short stories as they tend not to hold my attention very well. I'm much more interested in longer narratives that have time for you to properly get to know characters and watch them develop, but King seems to have a gift for extremely personal storytelling that gives you that feeling in 100 pages or less. I think people that dismiss him because of his genre or because of his (I think deceptively) simple prose are idiots.
Check this shit out. Watch the movies. Go nuts.