When I graduated from high school I didn't understand what the fuss was about. Celia is probably feeling the same way. Milestones don't mean as much when the years they mark are so few that they get along fine without them.
But parents of graduates know better. They know that rituals take us from one place to another. They know there are few moments when you can say that one thing has clearly ended and another has clearly begun.
High school graduation is such a moment.
So, hats off to the graduates ... and (if I may say so) to their parents, too!