Ironshield is correct in the overall reason for the deception. It's an overarching idea which cements all other deceptions.
However, there is a more practical reason for it. The following quote was ascribed to Hitler, though I am unsure whether he really said it: "Let me control the textbooks and I will control the state". Whether he said it, or not, is irrelevant. The point it makes is what's important. Controlling the mind of a child will give you control over that person for the rest of their life.
Today, our children are bombarded with the idea that the world is round and that we know so because Science and Space Organisations tell us so. They show us their telescopes. The child then grows up and goes to school, where they continue to trust the establishment, not their parents, about how the world works. By the time the child has become an adult, they are so indoctrinated that they will never question the way the world is, they will never question NASA, scientists, astronomers, possibly politicians. Even if they do question politicians, they will still support the academia blindly.
This is pure, perfectly executed mind control over the entire world. The Nazi psychologists and other interesting people would be proud.
How do you control someone's mind? By making them think that the world is the way YOU say it is.
Well said! Thought control over the masses.
@ironshield