To be the parent of young adults means getting used to the filling and emptying of the house that gave them birth. The house didn’t really give them birth, of course — I did. But sometimes it feels like it did, the rooms have so absorbed the people who grew up in them.

This old house has gotten pretty good at it by now. People move out, then in … then out again. The house accommodates it all — I just hang on for the ride.

Today is the last day of school in Fairfax County, a day my kids once celebrated with shaving cream fights at the bus stop, a celebratory fast-food lunch and the ceremonial viewing of one of our fave family movies, “The Music Man.” I hear the buses already, revving up for early dismissal. Soon they’ll be disgorging young’uns into an endless summer.

It doesn’t seem so long ago that I was meeting my own girls down at the corner. Now Celia (front row, left) is about to move in with her friend Jessy (standing right next to her), who lives … on the other side of the country.

It’s a grand adventure for all of us, the ones just starting out and the ones who’ve lived long enough to marvel at it all.