People who love reading are frequently disappointed by the movie versions of their favorite books. There have been some great films made from books, but typically, movie versions of books tend to frustrate readers because they are not just like the book. When a film director works from an adapted screenplay, the results are not the same as reading the book, for various reasons. For example, a film that precisely follows a novel likely would be too long for most audiences to sit through at a single showing, so some things must be left out. Also, a book can easily convey things to the reader that are much more difficult for a movie to convey, such as background information about the setting, the history, and nature of characters' relationships or even what characters are thinking at certain times.