There’s so much we have to teach our kids. How to tie their shoes. How to drive. How to do math. How to throw a football and hit a baseball. How to put up and down the toilet seat. How to clean up after themselves.

These are the practical skills of life. But they are worthless without other intangible personality traits–the ones we’ve talked so much about here: Kindness. Self-discipline. Work ethic. And most of all, courage.

“It was a high counsel that I once heard given to a young person,” Emerson once recounted, “‘Always do what you are afraid to do.’” It was advice that Robert F. Kennedy–father of 11–liked enough to underline in his own copy of Emerson’s Essays.

Without the ability to face our fears, to do what we’re afraid to do, we cannot grow or change. All growth, it has been said, is a leap in the dark. That’s scary! But good stuff is on the other side of the fear, the prizes and fruits of life can only be tasted through courage, through doing what at first intimidates or overwhelms us.

Make sure they know that. Along with throwing spirals and hitting fastballs, make sure they are doing things they are afraid to do.