Thou art banned for thy ignorance. For all small children are instructed in the ways of brain soap. In fact, the soap often bubbles from their brain into their mouth: thus the garbled speech of infants and small children. Traditionally it is applied by fairies, and when the children are old enough to use it themselves, the fairies leave a cake of it under their pillow every night. But when children refrain from using the soap regularly, the fairies stop bringing it, and it fades from their minds altogether. Thus the benefits of brain soap are lost, and the children begin getting "The Barney Song" stuck in their heads. This causes severe psychological damage and is responsible for most of the mental disorders in the population at large.