Christie Brinkley names her biggest regret: ‘God, what was I thinking?’

Christie Brinkley will soon be celebrating the big 6-5, on Feb. 2, and she's taking a look back at her decades-long career.

The American supermodel has been the cover girl of numerous magazines, walked on runways around the world and launched thriving businesses of her own. But the Sports Illustrated Swimsuit icon told ET Thursday she has one major regret.

“I didn’t do ‘Saturday Night Live’ when they asked me,” Brinkley told the celebrity news site. “God, what was I thinking?”

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One thing Brinkley is enjoying with age is confidence. She described posing for ET back in 1983 and feeling insecure then about her famous figure.

“I remember posing for that picture, thinking, ‘What am I going to do with my hips? Where do I put them so I don’t look so large?’” she recalled.

And while Brinkley is proud of her famous curves, she said there’s one major difference when it comes to being in your 60’s versus your 20’s.

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“You just don’t date that much,” the top model admitted.

Brinkley told Fox News in July 2018 during her Social Life Magazine cover party in Bridgehampton, N.Y., that she credited a healthy diet for her age-defying looks.

“I am a life-long vegetarian, so my diet is really, really good and I think your attitude plays a huge role too,” she said.

Brinkley is still celebrated as the first model to grace the coveted Sports Illustrated Swimsuit Issue three consecutive times in 1979, 1980 and 1981. She gushed about her memories of shooting for the iconic publication.

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“My Sports Illustrated adventures have been some of my favorites in my modeling career,” explained Brinkley. “It’s very hard to explain that feeling and the teamwork that happens and being in the most beautiful places, with the most beautiful light and being outdoors from when the sun comes up to when the sun sets.

“Working for Sports Illustrated is like you are outdoors looking for beauty the whole time… Working with a team and trying to create a beautiful image — it’s really special.”

In 2017, Brinkley stripped down for Sports Illustrated Swimsuit alongside her daughters Alexa Ray Joel and Sailor Brinkley Cook. Brinkley said she loved sharing the experience with her children.

Brinkley stressed that at the end of the day, she simply wants to enjoy life with her family.

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“People have got to stop and celebrate life and enjoy it and live it up!” she said. “And that is the fountain of youth. The secret to a great life is gratitude. If you can be grateful at any given moment that is the secret to being happy — just positive thinking.”

It wasn’t the first time Brinkley got candid about her looks. Back in 2017, Brinkley told PeopleStyle she isn’t afraid to rock a bikini — even when it comes to gardening.

“I always put a bikini on and say, ‘Oh, it is just to wear around the house. I am not going to go anywhere in it. I just want to get a little color while I am gardening,’” said the swimsuit model at the time. “I run around trimming my begonias to even everything out so I don’t have any tan lines.”

Brinkley insisted her reasoning is a simple one.

“When you’re naked, you want those parts tanned!” she said. “I don’t care how much sunblock you put on, when you’re outdoors as much as I am, you’re going to get some color.”

The ex-wife of musician Billy Joel also isn’t worried about critics commenting on her daring ensemble.

“You know what? You can’t really critique a person over 50 — it is just like, if they are brave enough to put on a bikini then you let them be!”

In 2015, Brinkley also told Fox News she maintains a daily workout regimen to always look and feel swimsuit-ready.

“I urge people to make your workout fun,” she advised. “Currently, I am doing a lot of bike riding. I like to do spinning classes and it’s just so fun.”

And when she can’t make time for an exercise class?

“I crank up the music and I dance around the house,” added Brinkley. “You don’t always have to get an expensive gym membership. The important thing is to keep moving, and to make it fun, and to have variety — it’s the spice of life.”