On Thursday morning, as children all over the region prepped for the new school year, John Fletcher was busy trying on his back-to-school outfit. He and his wife, Marybeth, admired the fit of his new blue blazer and Oxford shirt, and how well it paired with a new striped tie.

But as an 81-year-old retiree, he admitted that his ensemble had nothing to do with actually setting foot in a classroom. 

“There has always been something special about the first day of school,’’ said Fletcher, who spent more than 50 years as a teacher and principal in the Dartmouth School District. “It is a new beginning, and the excitement of that first day of school demands a new look.’’ 

The onset of fall can prompt a variety of emotional responses among shoppers. For harried K-12 parents, it’s a mad scavenger hunt to check all the items off the must-have list. For college students, it’s the gleeful independence that comes with outfitting a dorm room. Fashion aficionados hail the arrival of New York Fashion Week, Vogue’s Bible-thick September issue, and the appearance of the newest runway trends in stores.

And for a subset of the population who might be otherwise uninterested in shopping throughout the rest of the year, the first chill of autumn can spark a primordial urge to go back-to-school shopping, even if school itself is a distant memory.

“I saw on the news this morning that the children were going back to school, and it just triggered something,’’ said architect Vanessa Hancock, of San Francisco, as she wandered Newbury Street on Thursday afternoon, Lord & Taylor bag in hand. “I just needed to shop.’’ 

Suki Sporer was similarly inspired. “I bought plaid Balenciaga pants and a cashmere Marni contrasting V-neck vest,’’ the writer and former Harvard Business Review editor said as she strolled the shopping district. “I live in Austin and it doesn’t even get cold there really, but I had to have it.’’

The same urge occurred when Sporer recently visited the Michael’s craft supply store with her daughter, who is a teacher. “I hate Michael’s — but I was craving buying my kids pens and notebooks and binders,’’ Sporer said, even though her children are now adults. “It’s a psychological thing.’’

Barbara Bickart, a marketing professor at Boston University, said the arrival of fall brings to mind a feeling of renewal for some shoppers. “Ritual is the key word here,’’ she said, and recalled going back-to-school shopping in downtown Cincinnati with her mother as a child.

“We would go and have a big lunch. It was a thing you did and it was a special date,’’ she said. “There is a ritual around back-to-school that some of us want to relive. I think retailers try to trigger that.’’

Back-to-school is the second busiest time of year for stores, after the holiday shopping season, and will account for an anticipated $83.6 billion in sales this year, according to the National Retail Federation. But while research organizations poll parents annually about their purchase plans — Deloitte found that Boston parents planned to spend an average of $641 per student — they tend not to focus on the purchasing habits of adults who have no school ties to speak of. 

The desire to purchase new clothes every fall can be tied to seasonal changes that create a longing for longer sleeves and trousers. And unlike holiday shopping, which is altruistic at its heart, back-to-school shopping has always been about treating yourself. So while online shopping has become more routine for holiday purchases, “we still find back-to-school tends to be driven more to [physical] stores,’’ said Kate Ferrara, a retail analyst at Deloitte. Stores know this, and push sales this time of year in hopes of driving ancillary purchases.

“Retailers are really smart and know the customers well. They’re not promoting to fifth graders, but the moms who are getting ready to get their kids back to school,’’ said Ana Serafin Smith of the National Retail Federation. 

The local social analytics research firm Crimson Hexagon tracks mentions of retail trends, and found that when it excluded explicit references to ‘back-to-school’ on sites like Twitter and Facebook, there was still a significant uptick in online mentions of people going shopping in July and August during the last five years.

“There are still many questions to answer — What role do brands have in drumming up this conversation? What other factors influence this seasonal trend?’’ said Mike Baker, a senior content manager at Crimson Hexagon. “But it seems very clear from the data that retail shopping picks up just before the start of the school year, even for people who do not attend school.’’

These sales can also stem from an ingrained notion that we first learn as children that fall is the time when we need to shop.

“As a kid it was about looking for the latest Lisa Frank notebook or the cool Trapper Keeper,’’ said Peter Killian, an analyst at the Cambridge Group. 

And for some, it’s a sense of finally being able to have the back-to-school experience they lacked. Manny Lusardi of Cambridge grew up poor in upstate New York, and as the youngest of six boys, his parents rarely had the funds to purchase new outfits for the start of school. So for the last several decades, he’s purchased a new suit every autumn. 

“I start saving for a new suit every spring, with early September as the deadline for buying it,’’ Lusardi said.

The retired retail executive in Cambridge now serves as the city’s liaison for immigrant affairs, and he said the September suit is a small reminder of how far he’s come in life.

“A new suit has always been something special to me, something I like to celebrate in a weird way,’’ he said. “All summer long I think about where I’m going to buy it.’’

Janelle Nanos can be reached at janelle.nanos@globe.com. Find her on Twitter @janellenanos.