Christie Brinkley stopped by the Today show to discuss her new memoir.

Brinkley’s Uptown Girl, co-written with Sarah Toland and named after a song by ex-husband Billy Joel, was published Tuesday by Harper Influence. In the book, she tells the story of her life as one of America’s most famous models and her later career as an entrepreneur and activist for animal rights and the environment. A critic for Kirkus praised the book as “a thoroughly engaging glimpse into a colorful life well lived.”

Today co-host Al Roker asked Brinkley why she decided to write a memoir now.

“If not now, never,” Brinkley replied with a laugh. “I mean, at 71, I better get around to doing it. I’ve been asked for years to do it, and I started a couple times and then I thought, That’s so presumptuous. I’m not going to do this. But then recently, I was cleaning out my art studio, and I was thumbing through my journals.…Some of the stories in there, I go, Whoa! I did that?

Roker asked Brinkley if she let Joel know she was writing a memoir.

“I did speak with Billy beforehand,” she said. “He has a documentary that’s going to be opening up the Tribeca Film Festival, and we spoke before, and he said, ‘I want you in the documentary, and I want you to feel completely free to say whatever you want. I’m letting everybody know that they can just tell their story, the good, the bad.’ And I think that’s very courageous of him.”

Brinkley continued, “The only thing that makes me sad is some of the headlines have made it look like they’ve lumped together 11 years of a relationship and only plucked out a couple of the bad things that I wrote about when, in fact, it was…a really great part of my life.”

Michael Schaub is a contributing writer.