A note on Child Directed Play
"One of the joys of parenthood is watching your children engage in an activity that they love—pretending to be their favorite superhero, building castles in the sand, or painting a picture of their family. They are completely immersed in the activity, lose track of time, and are not easily distracted. Psychologists refer to this as a state of 'flow.'
Activities that lead to a state of flow are often child-directed, meaning children take charge of their own learning by exploring topics that they choose and are personally meaningful to them. Child-directed learning environments motivate children to learn because they are engaging in an activity for the sake of the experience."
Check out this related website The Genius of Play.