Christie Brinkley Reflects on Her Biggest Career Regret as She Celebrates a Birthday Milestone (Exclusive)

Ahead of her 65th birthday, ET sat down with the model who opened up about her earliest gigs and new projects.

Christie Brinkley has accomplished so much over her lengthy and successful career.

Ahead of her 65th birthday, ET's Kristine Johnson sat down with the supermodel where she reflected on her early gigs and new projects, as well as revealed her biggest career regret.

She's been on the cover of fashion magazines, walked in runways all over the world, starred in beauty campaigns and done so much more. So what did Brinkley feel like she missed out on? The answer is quite surprising.

"I didn't do Saturday Night Live when they asked me," she revealed. "God, what was I thinking?"

These days, Brinkley -- who looks better than ever -- has embarked on a new business venture, Bellissima Prosecco, and is getting ready to hit a huge birthday milestone.

She does, however, admit that there is one major difference when it comes to being in your 60's as opposed to your 20's.

"You just don't date that much," she candidly shared. She also admitted to still being overly critical of her image, even to this day.

"I remember posing for that picture, thinking, 'What am I going to with my hips? Where do I put them so I don't look so large?'" she said when looking back at ET's archival footage from a 1983 interview.

While Brinkley doesn't turn 65 until Feb. 2, she and her daughter, Alexa Ray Joel, celebrated early by throwing a party on Tuesday at the Gramercy Park Hotel in New York City. The top model looked regal in a sparkling gold and silver mini dress.

For more on Brinkley, watch below.