Ballerina Wendy Whelan discusses the moment her 30-year career with the New York City Ballet ended.

"Nobody should tell anybody else when to stop something," Whelan said on "Salon Talks." Whelan knows better than most how to keep going. Considered by many to be one of the greatest ballerinas alive today, she has enjoyed a stellar dance career, including a lengthy stint as a principal dancer for the New York City Ballet. But when she found herself facing a significant physical setback after more than 30 years in the spotlight, Whelan turned her odyssey into inspiration.

She now figures into Linda Saffire and Adam Schlesinger's new documentary "Restless Creature: Wendy Whelan," a portrait of an artist at a career crossroads. The film is a meditation on aging gracefully - from a world-class master of grace. After spending most of her life performing, Whelan knew the film would bring a different kind of exposure and at first she was hesitant to appear in it.

"All ballerinas want to show their perfectness as much as possible," Whelan said. "And I knew that this wasn't going to be able to do that because I was in a really fragile state," she added. "This is a pivotal moment in my life that most dancers don't show."

Watch the clip above to hear how Whelan learned to be emotionally flexible.