Jennifer Aniston's hair started one of the biggest style trends in America.

In the 1990s, Aniston's haircut, called "The Rachel," named after her character on "Friends," became one of the most imitated hairstyles of all time.

"It gave women the opportunity to feel effervescent and bubbly and excited and still be found attractive," celebrity stylist and product developer Josh Rosebrook told ABC News.

Now, the 44-year-old actress is opening up and revealing the truth behind the cut that changed everything, including her, in her new Living Proof webisode called "Good Hair Day."

Stylist to the stars Chris McMillan created the look because, he says, Aniston's hair was long and frizzy.

"Cut the bottom, layered it from existing bangs to bottom, took a bobby pin, pinned it over and blew it out smooth," McMillan explains in the video.

"And you know what happened after that …" Aniston replied, jokingly.

Aniston confesses she finds the obsession with her hair surprising, because she had an unmanageable mane.

"It's one of those things I think is hysterical," she said. "That me of all people, who grew up with the worst hair, is known for that."

And Aniston acknowledges how important hair is to a woman's self-esteem.

"I think good hair days matter to women because we're women," she said in the webisode. "Our hair means something to us. It just does."

The "Friends" star even confessed to Allure magazine in 2011, "I think it was the ugliest cut I've ever seen."

At the time, McMillan and Aniston didn't know they were about to create a phenomenon.

"It's amazing what a haircut can do," he said.

"They came to you, and then all of a sudden everybody started coming in with this flicky, flicky hairdo and I was like, 'What's happening?!" Aniston says, laughing.