In the preschool years, children learn much from repetition. They will return again and again to a favorite toy, book, or puzzle or a favorite set of materials, such as blocks.
Each time children play with these familiar objects, they learn something new about them.
That information was always there to be learned, but the child who returns to the familiar toy is not the same child who played with it a month ago.
Now he brings to his play everything that he has experienced and learned since the last time he handled the toy or material.
Because of this added experience, he is now ready to learn more from his present play than he could have learned a month ago.
The toy, puzzle, book or set of blocks is the same—but as the child brings more to the activity, he learns more from it.