Often, centenarians, people ages 100 and up, say their purpose in life keeps them going, which is why some never retire.

Deborah Szekely, 102, still runs her fitness resort and spa and shows up to work three days a week. She walks every day, sticks to a pescatarian diet and values her friendships.

"My life is healthy, and it is structured to be healthy," Szekely tells CNBC Make It. "You don't get to be 102, like, 'Oh, well, I'll make an exception here, an exception there.' I don't do exceptions. I enjoy my healthy life."

Here are some pieces of advice that Szekely has for living a long, happy life.

On working at 102

"I'd be very, very sad if I didn't feel I was helping people to have a better life," Szekely says. "It makes a change, and they tell me that."

"When I go and have breakfast, always right in the front of the dining room on the patio [of the resort she owns], people can come and tell me wonderful things," she says. "They all come to greet me and I'm there to be greeted. So they get happy and I get happy."

"When nature says, 'You got to stop Deborah.' Deborah will stop, until then she'll keep going."

On mindfulness and gratitude

"I don't really meditate. I don't. I meditate in action, in walking, in doing things," Szekely says. "My life is a meditation. I don't [focus on the] negative."

"I count my blessings, and I'm so blessed. [It's] very easy. I could spend all day and all night counting millions of blessings. I've been very blessed."

On friendship

"If you were to call them in the middle of night and say, 'Help!' [and] they'll be in their car in five minutes. Then there's the kind of friends that count."

"Friendship is understanding your friends, helping them. You know, recommending good books, movies, things we can do together."

On regrets

"I don't believe in looking back. I look ahead. I don't say, 'Oh, well, I wish I could do that or that.' That's a game. It doesn't give me any strength, any energy. I would rather read a book than look back."

"Don't waste time looking back. That's a total waste of time. You can't do anything about it, it's done. Look forward, and look forward to things that you want."

On dreaming

"Don't run out of dreams. Keep your dreams flowing. And realize as many of those that are feasible, and have friends to join those dreams. It's much more fun with friends."

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