Montaigne said he found nothing more notable in the life of Socrates than that he was very gifted at playing with children. In his later years, Socrates spent many hours playing games and giving children piggybacks for 'all actions, says philosophy, equally become and equally honour a wise man.' He did not deliver lectures to them.

Henri IV, the King of France, was very sweet around children. He once kept the Spanish Ambassador waiting while pretending to b a horse for his children to ride on. He did not sit on a throne discussing how to rule a kingdom.

The reason why we may feel tongue-tied and inept around shy five-year-olds or a moody 10-year-old is that children are unable to do any of the usual things that ease social encounters between adult strangers.

They don't ask polite questions about what we've been up to. They...