According to CNN, as of 2014 there were more than 70,000 living Americans who’d celebrated their 100th birthdays. While it’s hard for some of us to imagine what we’ll be doing if we’re ever lucky enough to reach that milestone, it probably goes without saying that "going to work" wouldn’t be our first answer.

Which is why none of us are Charles Carroll.

"I’m gonna go as long as I can go," says Carroll, 104, who for the last decade has spent 4 hours, twice a week, as a volunteer at Delray Medical Center.

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This World War II veteran and career Army man is the hospital’s oldest volunteer. He’s a wheelchair escort, the conduit between the sometimes scary, clinical world of the hospital and the bright sunlight of the outside world, pushing discharged patients in their wheelchairs to the front door so that they can continue their healing.

And it all comes back to a promise he made the first time he entered Delray Medical’s automatic glass doors - when he had a heart attack.

"I feel there’s nothing better that putting a person in a chair and seeing their expression," Carroll, of Delray Beach, says.

"It’s totally amazing," says daughter Judith Stern, who lives in Stuart, and is the one who first called the hospital to ask about her father working there. "He’s almost a member of the staff here."

The more you know about Carroll, the more it makes sense that his act of gratitude towards having his life saved would be work, because work is what he’s done, for nearly 90 years. As an adult, that work has been for the United States Army, as a private and as an MP, but he started as a kid working the tobacco fields "at 11 or 12." He also worked his way through the University of Massachusetts as a chef at a fraternity house.

"To tell you the truth, I didn’t have money, so I worked. I just liked what I did," he says, in that matter-of-fact way that guys from the Greatest Generation do when they talk about the things they did. "It worked out."

Becky McCoy, the hospital’s director of volunteer services, says that there are about 270 adult volunteers, along with 50 teenage ones in the summer. Carroll’s official job is to wheel patients, and to bring them deliveries of flowers, but his most important duty is "to bring cheer and joy," she says.

Ten years into his tenure, McCoy can now admit that she wasn’t completely sold on the idea of a new volunteer "who didn’t come to us till he was 90. We certainly cannot be prejudiced. I know he can physically contribute. At 104, he’s pushing wheelchairs. He’s all military. He walks tall and erect."

Carroll was born in 1913 in Springfield, Mass - "Being from New England, I’m a Yankees fan," he says wryly. He was the first person in his family to go to college, graduating from U-Mass in 1936 with a degree in landscape architecture. "When I got out, I could sell a bush," he says, again wryly, because that’s his sense of humor and it’s delightful.

From there, Carroll got a job at a school for boys in Yonkers, New York. But he had to go back home when his father fell ill and "I was his sole support." It was also a condition of deferring his induction into the military. When his father died of rectal cancer at the age of 40, the deferral was over.

"I took my first boat ride" to Casablanca, in Morocco, North Africa, where he followed General George Patton around. Having grown up ‘with snow 10 feet all around, moving to Africa was different," he says.

After being an enlisted man - one old enough to have had Civil War veterans visit his classroom as a kid - he decided that "I enjoyed what I did, so I decided to give it a whack" as a career, entering MP training school in Texas, another hot place. He met Helen Carter, a lovely young lady who worked for the government, and married her.

And, because she’d married a military man, Helen and her husband moved, first to Germany and then to the Washington, D.C. area, where daughter Judith was born. Son Barry was born later.

"My wife, she went with me everywhere. She supported me," Carroll says wistfully of Helen, to whom he was married for 68 years until her death in 2014. "She was just that way. She fit right in."

"She loved traveling," daughter Judith adds. "She liked new places."

Carroll was active in the Army for 25 years, and then worked as a civilian in Newport News, Va. "until I decided ‘That’s enough! I want to save a little bit for golf!’" he says. So he started volunteering at a golf course "so I could play for free, to tell the truth." He even taught Helen to play.

But when he had a heart attack in his 90s, he was taken to Delray Medical, "and they fixed me up." To his chagrin, he had to stop playing golf - "I still have my clubs, if anyone is interested" - but was still able to volunteer. And that’s why his daughter "picked up the phone and said ‘My dad would like to (be) a volunteer. And he’s 95.’ There was a silence on the phone," she remembers. "We all make judgments."

A decade later, everyone involved is glad those judgments were fleeting.

Carroll isn’t the only elderly volunteer at the hospital - there’s another current worker who’s 96. McCoy says the older set fills a variety of roles, greeting at the information desk, or even participating in the Caring Clown program. His presence, however, is also a great advertisement for the volunteer program as a whole, because "he’s so inspiring to the new volunteers. He works with a mission."

So what’s the secret of his longevity?

"I really don’t know," Carroll says, laughing.

"Well, there’s luck involved," his daughter offers.

"I just like doing things," Carroll concludes.