Christie Brinkley may be one of the most famous supermodels in the world, but once upon a time, she was just a dog owner trying to call a veterinarian.

In an interview with WWD, Brinkley revealed that she stumbled upon modeling by accident while trying to take care of her sick dog. While she was living in Paris—as an artist, not a model—she bought a puppy named Tempête. When Tempête became ill, Brinkley had to walk to an office to call at veterinarian (this was a pre-cell phone era).

Her life was never the same again.

“I walked into the telephoning office and this guy goes, ‘I was waiting for you to come back. I’m a photographer and I’ve got my first big job. I was thinking you have the look that they described. Will you do it?’” she said. “It was thanks to my puppy that I thought, ‘Let me just see what it’s like and do one little thing.’”

It seems like she owes Tempête a gigantic thank you.

Brinkley is still working as a model today. She recently shot a Sports Illustrated spread with her daughters Sailor and Alexa Ray, and she consistently brings her A-list style to the red carpet. She's worked hard for a lengthy and successful career, but she didn't always think that was possible.

VIDEO: Christie Brinkley and Her Daughters Pose for Sports Illustrated's Swimsuit Issue

"In the olden days, they used to say a model would be chewed up and spit out by the time she was 30 and that you, just like an athlete, have your years when you’re going to have your work and you need to exploit that moment," she said. "It’s wonderful that my industry is embracing all forms of diversity in beauty and that is now also including breaking that ageism barrier that we have allowed women in America to be defined by. They’ve been almost like prisoners of these rules that are supposed to apply to women over 30. It’s so great to see that changing as well."

The changes are certainly positive and helpful, but if you want to be model-ready at Brinkley's age and beyond, you should listen to the advice she gives her daughters. Brinkley said aging gracefully has a lot to do with attitude.

"Eat right, exercise and sunblock are the three things that will affect your outcome more than anything, as well as a healthy attitude," she said. "An attitude of gratitude is the formula for a happy life and I truly believe that happiness contributes to your wellbeing and to your health."

We couldn't agree more.