To demand of a child that they master or perfect what currently interests them is to teach the child apathy, frustration and contempt. Children flit from one subject to another, or even to no specific subject. Their attention spans are limited to the momentary experience of wonder, the puerile assessment of the unknown, and the possible inquiry for more information. This could take less than a minute with a young child, and may last for years with a much older child. Childhood is not adulthood.
Childhood is a time of play and no child of restricting parents ever gets enough play.
If this stage is repressed, flightiness may continue into adulthood. For a child, a large amount of fickleness is natural and temporary and in an adult it is not. Unrealistic expectations and demands serve only to inhibit the child in his natural pursuit of what causes him happiness and satisfaction. Some parents begin their relationship with their children teeming with faith a faith that the child is good and will turn out fine as long as the child is neither spoiled by unreasonable permissiveness, nor squashed by the psychological hang-ups of Mom and Dad. It is a difficult challenge for parents and all libertarians to not exercise our freedoms without displacing another's, or to allow another's freedoms to displace ours.