I read the story only after I saw the movie.
I was deeply disappointed.
I was in my most devastated and heartbroken state after experiencing the shock of BBM, and I was desperate to find out more about Jack and Ennis. Hoping that the story would give me more information about them that the movie did (which is usually the case), I ordered the book in Swedish translation. But, the story contained even less info about them! And besides, it was written in such a strange language, I wondered if the translation was bad.
So I bought the English book as well, where the language was just as strange! Didn't make me find out one bit more about Jack and Ennis!
Later, I've come to appreciate the story a great deal, but it will always be the movie that had such an unexpected and huge impact on me and changed my life.