Why is it important to know What is fake of real in parts of a story or book or television programs?

You need to be able to tell what is true or not. This is part of abstract thinking and it allows you to know the truth from a lie. If I told you that the earth was the center of the universe and you couldn't think this out you might believe me. If you believe that then I can lie to you about anything. I can sell you anything or tell you things that could change your life. I see a lot of this sort of thing in history and if repeated often enough the lie becomes the truth. School tries to teach you these things through reading so you can make educated decisions.