First off in the movie Walter Mitty goes on an adventure, but in the book Walter doesn’t. What’s the fun in not seeing an adventure? Let’s be honest the movie adventure is funny and action packed and is more fun than daydreaming. For example in the movie he almost gets eaten by a shark in real life. In the book the only fun thing is when his wife gets mad at him for not paying attention.
Another reason that the movie is better than the book is because it’s longer and tells more of the story. For example in the book all that happened was he was taking his wife