BELLINGHAM, Mass. — The secrets to bagging groceries are just “common sense,” Sal Pilla said as he grouped refrigerated items in one sack and fruits and vegetables in another on checkout lane 6 on a recent Friday morning.

But working at the Bellingham Market Basket may be part of the secret of his success.

After all, not many bag boys are 93.

Not that bagging is his only role at the Stallbrook Marketplace supermarket.

“He does everything,” said store manager Steve Dunn.

Nor are his three shifts a week the only times you’ll find him at work.

“He’ll come in even on his days off, directing traffic (of shoppers to a less crowded checkout line), taking the bakery trash out. … He comes in Sundays after church, talks to all the customers,” said Dunn.

“Sometimes he has more energy than the kids.”

Pilla, who keeps cookies in his pocket “to give to certain people,” was 77 when he started the Market Basket job.

By then, he had worked for Draper’s for 30 years in the foundry – “They called me ‘Scrap Iron’ when he served as a sergeant in the Army National Guard – and had also been a Bellingham firefighter for 20 years.

When he first visited the store, he seemed to know just about all the shoppers, so “they asked if I wanted to work here,” and his late wife, Blanche, agreed it might be a good idea.

“I’m a people person,” said Pilla. “I can’t sit in the corner by myself. I just can’t.”

When he’s not working, he can often be found dancing.

Back in the day, he cut a rug at local hotspots like Norumbega Park and Lake Pearl.

Now you’re more likely to find him at the Uxbridge VFW, Medway Senior Center or, if he gets off work in time on Friday afternoons, the Holliston Senior Center’s Big Band sessions.

He’ll do the polka and line dances, but prefers the waltz.

“I like to do together dancing,” he said. “I like to hold them tight.”

His dancing days started early, back in Milford, where he grew up.

“My father played the accordion. My sister and I used to dance. And I haven’t stopped.”

Milford was also where he learned, when he went to get his driver’s license, his real first name is Salvatore.

Old friends like former state Rep. Marie Parente still call him “Johnny,” since his family always called him by his middle name in honor of an uncle who died. “You could never call me Sal in front of my sister,” he said.

It’s also where he found his first job, as a stock boy at F.W. Woolworth’s.

His wife-to-be “was my next-door neighbor. I told her I’d marry her when I came back” from World War II. At 20, and a member of the National Guard, “I was an old man” compared to many of his fellow GIs.

Serving with the 5th Armored Division in Europe, “that’s when I met George” Patton. “He was a soldier’s soldier,” who “told us ‘You don’t salute in the field.”’

Pilla, who served in “D-Day Plus One” and the Battle of the Bulge, remembers Patton or one of his staff officers was frequently on the front lines.

The bonds forged in combat are not forgotten.

“We knew each other. Everybody took care of everybody,” said the man whose dog tag remains on his key ring almost 70 years after the war’s end.

He returned home and married Blanche, and the couple lived in Milford for about eight years before moving to Bellingham, where they raised two sons.

“I volunteered with the fire department at first,” he said, but later became a lieutenant and ladder instructor. While most of those he trained are now retired, “they remember the old man got them up on the roof.”

At 93, his doctor tells him “don’t change a thing you’re doing,” so he still drives, though not at night, and he still shows up to work, even on days like a recent Friday, when a light snow blanketed the parking lot and temperatures struggled to get out of the teens.

“I don’t have stress,” he said.

He does, however, have an occasional word of advice for his teen coworkers.

No matter what your age, “You serve the customers. They don’t serve you.”