The worst thing about my book

The worst thing about my book is it's very confusing. I know the author probably made it confusing so you can think and use your context clues and predict. I'm finding some of the details are very different from the movie. I feel the book is more confusing because you don't really have a visual only the one you make in your head. I'm very confused on why the girls friend hasn't met anyone else on the island. Why is she the only one that has met her? If you have read the book and the movie, what do you find that is different from one another? Are a lot of the details the same or different?