It’s a common occurrence, I think, to tell someone about a movie you just saw that you personally believe to be very good. You tell them that you thought the acting was great, the story was emotionally resonant, and that you just had an overall great time watching it. Suddenly, your friend, who has been very eager to speak since hearing the film’s title, chimes in saying “if you think that was good, the book is ten times better!” The question is why they believed the book was better than the film, despite them liking the film, too.
This is a very normal thing when a book is adapted into a film. From the announcement of the project, fans of the source material are filled with excitement and place expectations on the film based on what they experienced while reading. I’m pretty sure we’ve all done this; I did it multiple times before, but every time this happens, it also leads to fans saying the book was better.
This, specifically, happens when the movies are pleasant and faithful to the book, and it’s even worse when the movie is bad or just completely doesn’t do the original any justice. A novel is a longer and more investing experience, you normally go through a book in a couple of days or even months. There is so much nuance and complexity that a story loses when it is adapted into a film, that you would feel as if the book were superior. The other aspect is that, when reading, you paint your own picture in your head of how these characters look and act.
It’s only natural that fans would say the book is better, so maybe next time you hear about a film adaptation for a popular book, you should look into reading it first.