My son Mark was only 5 feet, 8 inches tall when he left for college in the fall. He worked through the Christmas holidays and didn't return home again until the February break.

When he got off the plane, I was stunned at how much taller he looked. Measuring him at home, I discovered he now stood at 5 feet, 11 inches. My son was as surprised as I. "Couldn't you tell by your clothes that you'd grown?" I asked him.

"Since I've been doing my own laundry," he replied, "I just figured everything had shrunk."