one reason is you can play the book out how you want to, imagine the characters your way, what the place looks like, etc. With a movie that is taken away from you. You are told how everything looks, and the movie/TV van leave out many stuff from the book
I have learned that you need to study and do your homework to pass highschool. I also learned that you need to ask for help when needed, if you don't you could face really big problems in school.