The child's mind is naturally more active than a grown-up person's, for two reasons. Firstly, the child's mind is growing with great energy, which makes it active during its growth. Furthermore, energy is active in its rise and loses power in its descent; it is for this reason that the child is restless in its thought and action. One child in the room can make one feel there are a hundred children. The child is never still, it delights in occupying its mental and physical energy in some way or other all the time.