Creating films from books is nothing new. Since the dawn of cinema, screenwriters have taken the success of literature and used that to create cinematic masterpieces. One of the earliest films I can think of – Gone With The Wind (1939) – was adapted from a book that was published 3 years prior.
However, films are not books. They are materially different media and to make a point of comparing a film to its literary genesis is pointless. If you’re a fan of literature – creating characters in your mind and taking artistic license to join the dots in the story – then by all means continue to do so, but to expect the same experience from a film is foolish.
Films (for the most part) remove much of the creativity from the viewer almost by default, because they have to show who the characters are, where they live, what they do and so on (by the very nature of using video). As such, things are more spelled out. Additionally, because of how films are consumed, it is impossible to give as much detail as is given in a book, which is poured over for days or weeks.
So the next time you watch a film adapted from a book, please refrain from uttering
It wasn’t as good as the book
because that’s like saying that a horse ride was “slower and less comfortable” than riding in a car (of course it is, but you were probably riding the horse for a reason other than trying to get somewhere quickly and comfortably).
Take the film for what it is and enjoy both as separate pieces of art with a moderately common story line.