At my fifth and last child’s high school graduation, I settled into a seat next to a gentleman who was the father of another graduate. When the ceremony ended, most of the parents excitedly rushed forward to take photos of their sons and daughters. But this fellow just sat there in a classic dejected pose, his hands on his cheeks and his elbows on his knees. He appeared numb rather than jubilant, not what you expect from a proud parent of a child who just earned a high school diploma. “Are you all right?” I asked. “Have I ever messed up,” he replied. “This is the first moment it’s hit me that my little girl will be headed to college in a few months and I have to start paying for her...