EVERYONE assumed I was going to fall into a depression after my twin sons went off to college — and so did I. I heard stories about women lying down on the distant child’s bed and sobbing and I thought, “That’s going to me.”

To my surprise and everyone else’s, nothing like that happened; I found I thoroughly enjoyed my new life. But before I arrived at that happy discovery, one unusual thing did happen: For several months, starting in the summer and extending all the way through November of their first semester away, I developed a strange relationship with Bed Bath & Beyond. For a while, that soulless warehouse full of sheets, towels and “as seen on TV” gimmicks seemed to be the only entity in the world that really understood how I was feeling in those delicate days.

There was a time in my life when I thought I would never get through a week without stepping barefoot on the sharp side of a Lego. Then there came a time when I looked around and realized there wasn’t a single Lego in the house anymore. One minute I was feeding quarters into little bouncy cars that my sons were sitting in, the next minute they were driving away from me in a real car. I started counting their time left at home in weeks, and a gloom descended on me. In a funk of sadness and loss, I grabbed one of my sons and headed over to the Bed Bath & Beyond on Hollywood and Vine — where my mood began to improve.

Inside the big, windowless store, I was directed to the little office where engaged people register for weddings. A cheerful young man behind a desk shook our hands and asked my son where he was going to college. It seemed silly — we were just there for sheets and towels! — but it made going to college seem as big a life step as getting married.

The salesman asked him the name of his college and assigned dorm, then typed them into the computer. There was the click and whir of a printer, and then he handed us a miraculous document: a sheet of paper listing what we needed to know about dorm rooms at Kenyon College, what items the college would provide, what we could and could not bring, and what we might want to buy.

Here we were in Hollywood, Calif., and yet we were already linked to the BB&B in Columbus, Ohio, with turn-by-turn directions from his dorm to the store, where on move-in day we were to pick up the things we’d chosen. It was many months later, poking around on the store’s website, that I realized that the hundreds of lists in the database are, of course, essentially the same — every dorm provides a dresser, a desk and chair, a wastebasket; every college allows you to bring an alarm clock but not an “open coil appliance.”

But with my son beside me — during his last weeks as a full citizen of my home — BB&B had performed a bit of profitable magic. The latest thinking in retail is that a brand exists, ideally, within a relationship. You aren’t exchanging money with McDonald’s for a hamburger. You are making McDonald’s part of your life story.

I have always hated this kind of consumer manipulation; yet looking at that piece of paper, I felt that what was once merely an impersonal chain store was now a group of people who understood what I was feeling.

I was not feeling a sadness about losing contact with my boys. In this age of texting, the Sunday-night phone call and long-awaited letter are things of the past. What I was sad about was losing their physical presence in my life, which I’d been thinking about and caring for since I made up their cribs a month before they were born. Bed Bath & Beyond wasn’t saying, “Get over yourself!” Bed Bath & Beyond was saying, “You go, girl!”

IF you ever happen to be near a freshman dorm in early May when students muck out their rooms in preparation for going back home, you will see an astonishing, growing mountain of consumer goods, still in their boxes. The students haven’t seen these things since their mothers stowed them away in their dorm room drawers and closets back in August: Dustbusters, first-aid kits, irons, collapsible hampers, organizing bins and baskets, extra blankets, flashlights, extension cords, drying racks. And much of this will end up in the rummage sale or charity drive organized by some campus club.

These mountain ranges of stuff represent good news to big-box America, where back-to-college shopping is an even bigger business than back-to-school shopping. According to the National Retail Federation, these shoppers will spend a record amount this school year: $54.1 billion on items like clothes ($8 billion), shoes ($4.5 billion) and electronics ($12.8 billion). They also will spend more than $5.9 billion on bedding, coffee makers and mini-microwaves, what retailers call “dorm room essentials.”

One profit center is the bed itself, for the new college mattress is quite a bit different from the one I confronted in the fall of 1979, which was lumpy, stained, covered in gray and white ticking, and resting on a set of wire bed springs, an unsightly object that my mother quickly covered with a mattress pad and fitted sheets — both taken from her linen closet — and my favorite quilt.

The modern dorm mattress looks like something you’d find in a gymnastics class: a rectangle of unyielding foam with springs deep inside, all of it covered in dark blue vinyl or waterproof nylon. It’s a mattress that keeps its secrets, requiring only a spray of disinfectant by the summer cleaning crew to make it an unstained object without a past (it has typically passed something called the ASTM Method F-1670 Liquid and Synthetic Blood Penetration Test).

Because colleges use twin XL mattresses (on the assumption that there must be enough students over 6 feet 6 to necessitate everyone getting an 80-inch-long bed), there’s a brisk business in selling sheets and bedding to fit. The blocky firmness is the reason many students now have mattress toppers — padded layers of foam or down to set atop the mattress. They vary in price, all the way up to the Cadillac of the category: the Tempur-Topper Supreme that costs close to $300.

Why would anyone spend $300 to make a dorm bed softer? The short answer is that in our country of savage inequalities there are plenty of people who can afford to pad their college experiences against any possible hardship, even a too-firm mattress. The longer answer is that children’s departure from the family home evokes a rich mix of potent emotions of the kind that marketing experts spend considerable effort trying to exploit.

Everyone is going to try to get you to shop your feelings away — sometimes even the college itself. New York University told us several times that Bed Bath & Beyond was a good place to buy things for the dorm — and to prove it, the store hosts an annual all-night shopping party open only to N.Y.U. students and their credit-card-wielding parents. (I was given a cold shoulder from the company on the nature of its relationship with the university, but I did learn that 15 percent of all sales go to the N.Y.U. student government’s activities fund.)

In the manner of a public service, allow me — as someone who has awakened from the expensive, temporary spell of dorm room madness — to tell you that what you really need to buy for your kid’s dorm room is … almost nothing.

You should get the XL twin sheets because its easier to make the bed that way, but the rest of the bedding can come from home. Ditto the towels. If the bed’s too hard, turn the mattress over: Many are constructed so one side is firmer. If you still want a mattress topper, Walmart and Target sell them dirt cheap. If he needs an iron, you can have it to him in days — hours — via the power of online shopping. If she left a winter coat at home, stick it in a box and mail it to her.

The best recommendation my boys got was from my sister, who advised them to bring a couple of sentimental items from home. And so it was that my old copy of “Franny and Zooey” went to college again, and (I noticed) was the first thing pulled from the suitcase and propped up on the bookcase.

These college freshmen are not eager to start ironing and vacuuming. They’re eager to put you back in the rental car and to get started.

The best thing you can do in these tense final hours is to breathe deeply and remind yourself: A semester is four months long. This isn’t induction in the armed services; it’s basically sleep-away camp, with better food and the same vinyl-covered mattress.

On move-in day, the doors of the freshman dorm rooms are open, and up and down the hallway you can peer into them and see mothers making their last stand. Fathers are mulling around making suggestions that are batted away, and are occasionally handed boxes for the Dumpster, while mothers are making beds with an emotional intensity that is only understood by one another.

Then they all run outside, grabbing their purses for some last-minute shopping, making purchases that are not spurred by rational thinking. The Brita filter is bought as a complicated way of saying something best expressed in a line of Delmore Schwartz poetry that I kept trying not to think about in those delicate last hours:

“Abide with me: do not go away.”

I had only one moment of the kind of reckoning I’d been dreading all summer, or perhaps for the past 18 years. We’d dropped the first son off in Ohio, the second in New York, and I’d stayed around for a couple of extra days in case I was needed (I wasn’t). On my last day, I met him at a coffee shop near his dorm. We sat in the sunshine with cold drinks, and he seemed to me impossibly young to be left there — as young, I’m certain, as I must have seemed to my own parents in 1979.

And then it was time to go to the airport. I hailed a cab, and my son heaved my suitcase into the trunk. I hugged him one last time, as quickly as possible, and got in the cab.

And then I watched him disappear into a jostling New York crowd, headed in the general direction of his memory foam mattress topper and his new life.