Because the children were rarely bored – at least, when a television
was nearby – they never learned how to use their own imagination as a
form of entertainment. “The capacity to daydream enables a person to
fill empty time with an enjoyable activity that can be carried on
anywhere,” Belton says. “But that’s a skill that requires real
practice. Too many kids never get the practice.”

[…]

“The point is that it’s not enough to just daydream,” Schooler says.
“Letting your mind drift off is the easy part. The hard part is
maintaining enough awareness so that even when you start to daydream
you can interrupt yourself and notice a creative insight.” — Jonah Lehrer, The Boston Globe