Iris Apfel Celebrates Turning 100 by Sharing Her Best Lessons on Love, Life and Plastic Surgery

The days leading up to Iris Apfel's milestone 100th birthday (on Aug. 29) were spent doing what she loves most: working.

"At 100, what else is there to do except sit around? I don't play bridge. I don't play golf. I love to work, and I really enjoy what I do," the style icon tells PEOPLE exclusively in this week's issue. In the last week of her 99th year, the model and muse launched an eyewear line with Zenni Optical and has several more projects coming up.

Keeping busy is just the way Apfel works best. "I'm the Energizer Bunny," she shares. "Once in a while, I give out, but I'm a black belt multitasker. I have to do a few things at once. I never even could read one book at a time. I have to read three books. That's the way my head operates."

The self-dubbed "geriatric starlet" will find time to celebrate her birthday later, with a party alongside her (fully vaccinated) guests at Central Park Tower in New York City in September. "I'm looking forward to seeing a lot of old friends from a lot of offbeat places."

"The pandemic has made me kind of a hermit," she adds. "I'm a very social person, but I saw no one during the pandemic; it was just me and my thoughts. You have to have projects."

Apfel knows something about having projects; she's been working nonstop since 2005, when Apfel, then 84, became an overnight sensation after the Metropolitan Museum of Art put her extensive fashion archive on display. When an exhibition at the Met fell through, curator Harold Koda asked Apfel if she'd show her extensive costume jewelry collection.

The pieces (which she acquired during her many travels working for her prestigious fabric company, Old World Weavers, which she ran with her late husband Carl Apfel) were styled with her own outfits and signature glasses, showing off her playful, idiosyncratic approach to fashion — and made her an overnight sensation in the fashion world.

"I never expected to be a celebrity," Apfel says. "I had no agent at the time. I've never had a business plan, but opportunities came, and I took them." Those opportunities included designing fashion, beauty and home decor lines with major retailers like Macy's, MAC Cosmetics and Lowe's, starring in a self-titled documentary in 2014 and signing with IMG Models at 97. Today, she has 1.9 million Instagram followers who constantly show their love for Apfel by creating fan art in her likeness.

For more on Iris Apfel, pick up this week's issue of PEOPLE on newsstands Friday.

"When people tell me that I've helped them and given them courage, it makes me so happy," she says. "It's very rewarding."

Below, Apfel shares what she's learned about getting older, dressing up and accepting yourself, wrinkles and all.

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"I really don't feel any differently than I felt a couple of years ago. The doctors treat me like a coddled egg, and I try to be as careful as possible, but I don't have an organized [wellness] plan. I have always eaten very well. I trained myself to never eat junk food. I don't drink soda and very rarely drink [alcohol]. Periodically I exercise. It's a matter of the way you look at things. I know 30-year-old people who are old and 90-year-old people who are young. Everything is your attitude. When you think about things a certain way, you look a certain way."

"To me, wrinkles are a badge of courage. If God is good to you and gives you all those years, why try to hide it? I don't believe in plastic surgery unless, God forbid, you're in an accident or you were born with a nose like Pinocchio. Otherwise, just to be nipped and tucked? It's so foolish, because after a while you get to look so pinched and nobody is going to think that you're 27 if you're 72. You can't make your hands look younger. And what's wrong with white hair? I used to take so much abuse — people who were supposed to be my friends used to say, 'Why don't you become blonde?' Fortunately my husband liked gray hair, so I never [dyed] it."

"Style is in your DNA. You can learn to be fashionable and to have good taste, but style is something within. It's a matter of attitude. It's the way you look at things, the way you think about things, and it's the way you present yourself. And the best way to do that is to be yourself, not try to copy somebody. I can't tell you how to have style. I don't know why all the young people today want to look the same. I find it so sad. I think they're missing so much. Your originality is so important."

"I had 68 years of a beautiful marriage. Carl died [in 2015] three days before his 101st birthday. At first I was just crushed. I didn't think I could manage, but I realized one day he wouldn't want me to sit around and mope, because he was like a stage mother. He really did push me. I had opportunities which I thought he would say, 'Oh, forget it.' But he'd say, 'No, do it. You got to do it.'"

"When I was about 10, my mother decided to go back to work, and it was terrible for me. I thought my mother had forsaken me. And so I decided if I got married and had a career, I would never have children. You can't have everything, and life is full of making choices."

"If you make a federal case out of everything, you're going to be a wreck. You can't live in the past, because that's gone and you can't make it come back. It was lousy, it's finished, go on to the next mistake. As my husband used to say, 'You have one trip, baby, so enjoy it.'"