On Saturday we stand for hours at an outdoor concert. The sun beams at us on a mild early spring day.

Near the front of all the action, young parents form a loose circle around their toddlers, some of whom are bobbing in time to the music. One clings to her mother’s leg. Another picks at stones lodged in asphalt, determined to get something in his mouth.

I catch Mike’s eye and nod at the group, so happy we are no longer them. He smiles.

Our own kids have likely not moved from the family room sofa where we left them with their screens full of post apocalyptic warfare nonsense.

Later I will kick them out. No longer with the admonition to “go play,” but with the reminder that one of them wants to run a half marathon this summer. He needs to train. I’ll run with him in intervals, moving at his pace, encouraging him to stop hoping over tree limbs and puddles, or doing parkour on retaining walls or fences. He needs to conserve energy for distance.

He’ll poop out anyway, halfway through and I’ll have to encourage him.

“Pick a pace and, keep moving. There is no stopping until you’re done.”

He was once the toddler in our protective circle. Before that he was our dream of a young family, holding me hostage on the couch, my legs crossed under a swollen belly. Back then, his lack of movement caused panic.

I shoveled in cookies and juice, waiting for a sugar rush, and then heaved a sigh of relief when my skin bulged first on one side, then the other, like an alien in a horror movie waiting to erupt from my insides.

Soon after that, he was our tow headed terror, pulling everything off shelves, likely to bolt into traffic from a parked row of cars. Cajoled into a moment of stillness at church by a new trinket, a scrap of paper and pen, or piece of fruit candy.

“I don’t remember you girls being so active,” mom told me. I don’t remember anyone moving so much, I thought.

How we ever traveled with him and then later his brother, is testimony either to bravery or stupidity.

“Move away from us at any time, and we might lose you,” we said terrifying them both into stillness on a train, in a crowd, or in a store.

We developed emergency plans we hoped never to need, and scared them into holding hands when they thought themselves too big for that.

Here we are a short time later, when they barely move until prodded out of bed late in the day, only to plant themselves in front of a screen until mealtime.

The once towheaded terror pulled an application for driver’s training from a site online, and I began to imagine him moving along the freeway, exhilarated by freedom, while I wait anxiously, not certain the protective bubble I manifest in my head will keep him safe from sleepy semi drivers and distracted housewives.

Not too much longer they’ll move away altogether, first in fits and starts and then forever. We’ll shed the space and the furniture and move ourselves, to far-flung places with no kid menus or need for emergency plans lest some pint-sized person gets lost in a crowd.

For now, I watch other people’s toddlers dance, and wonder at their ability to interpret a beat, to explore rhythm with their pudgy limbs, while the one keeps working to move a single stone lose from the asphalt to sample on their tongue.