I wrote this column 15 summers ago when my friend’s twin girls were going off to college. Every August when this column runs, a new set of readers responds. Times change, circumstances change, the whole world changes. But feelings do not.

Saying goodbye to a child always was and always will be hard. This year saying goodbye is even harder. Parents spent nearly a year in lockdown with their kids. And now they’re watching them pack their bags. Life does go on and it might even be a great, wonderful, exciting life. But the truth is that letting go hurts.

I wasn’t wrong about their leaving. My husband kept telling me I was. That it wasn’t the end of the world when first one child, then another, and then the last packed their bags and left for college.

But it was the end of something. “Can you pick me up, Mom?’’ “What’s for dinner?’’ “What do you think?’’

I was the sun and they were the planets. And there was life on those planets, whirling, non-stop plans and parties and friends coming and going, and ideas and dreams and the phone ringing and doors slamming.

And I got to beam down on them. To watch. To glow.

And then they were gone, one after the other.

“They’ll be back,’’ my husband said. And he was right. They came back. But he was wrong, too, because they came back for intervals — not for always, not planets anymore, making their predictable orbits, but unpredictable, like shooting stars.

Always is what you miss. Always knowing where they are. At school. At play practice. At a ballgame. At a friend’s. Always looking at the clock midday and anticipating the door opening, the sigh, the smile, the laugh, the shrug. “How was school?’’ answered for years in too much detail. “And then he said . . . and then I said to him. . . .’’

Then hardly answered at all.

Always, knowing his friends.

Her favorite show.

What he had for breakfast.

What she wore to school.

What he thinks.

How she feels.

My friend’s twin girls left for Roger Williams yesterday. They are her fourth and fifth children. She’s been down this road three times before. You’d think it would get easier. “I don’t know what I’m going to do without them,’’ she has said every day for months.

And I have said nothing, because, really, what is there to say?

A chapter ends. Another chapter begins. One door closes and another door opens. The best thing a parent can give their child is wings. I read all these things when my children left home and thought then what I think now: What do these words mean?

Eighteen years isn’t a chapter in anyone’s life. It’s a whole book, and that book is ending and what comes next is connected to, but different from, everything that has gone before.

Before was an infant, a toddler, a child, a teenager. Before was feeding and changing and teaching and comforting and guiding and disciplining, everything hands-on.

Now?

Now the kids are young adults and on their own and the parents are on the periphery, and it’s not just a chapter change. It’s a sea change.

As for a door closing? Would that you could close a door and forget for even a minute your children and your love for them and your fear for them, too. And would that they occupied just a single room in your head. But they’re in every room in your head and in your heart.

As for the wings analogy? It’s sweet. But children are not birds. Parents don’t let them go and build another nest and have all new offspring next year.

Saying goodbye to your children and their childhood is much harder than all the pithy sayings make it seem. Because that’s what going to college is. It’s goodbye.

It’s not a death. And it’s not a tragedy.

But it’s not nothing, either.

To grow a child, a body changes. It needs more sleep. It rejects food it used to like. It expands and it adapts.

To let go of a child, a body changes, too. It sighs and it cries and it feels weightless and heavy at the same time.

The drive home alone without them is the worst. And the first few days.

But then it gets better. The kids call, come home, bring their friends, fill the house with their energy again.

Life does go on.

“Can you give me a ride to the mall?’’ “Mom, make him stop!’’ I don’t miss this part of parenting, playing chauffeur and referee.

But I miss them, still, all these years later, the children they were, at the dinner table, beside me on the couch, talking on the phone, sleeping in their rooms, safe, home, mine.

Beverly Beckham’s column appears every two weeks. She can be reached at bev@beverlybeckham.com.