"Train up a child in the way he should go; even when he is old he will not depart from it." - Proverbs 22:6   The backyard was not much to look at. The grass was patchy in places, and the swing set had seen better days, but on a random Tuesday afternoon, it was the center of the universe. A father sat on the back steps, watching his daughter try to master the art of the cartwheel for the fiftieth time. He had a mountain of work waiting for him inside, and his phone buzzed in his pocket...