Although your senses register the movement, your mind knows that the sun is not moving. Though you feel stationary, you know the earth is spinning on its axis. Your mind knows that movement of the sun is an illusion, and that in truth you are moving. Comprehension of this illusion requires abstract thinking. A young child cannot figure it out.
Schoolteachers notice a shift from concrete thinking to abstract thinking in a child's development.
In most cases, the shift happens practically overnight. One day, the student can't even begin to understand an algebra equation, and then suddenly, when the brain is ready, the student gets it. If the brain is not yet ready, no amount of instruction will help a student understand. To comprehend or recognize an illusion, the brain must reach a certain level of development. As a child reaches twelve or thirteen, the brain has developed enough to comprehend concepts adults assume are obvious.