“Don’t ever underestimate the importance of storytelling. You are your greatest competitive advantage,” Blakely tells Fortune. It’s a mantra that helped her take her $5,000 in savings from selling fax machines and turn it into a $1.2 billion women’s shapewear empire.

When she first started Spanx, she deliberately kept her idea hidden—even from her closest friends and family.

“Ideas are the most vulnerable in the moment you have them. I waited a year before I told any friends or family what I was working on and that’s because I didn’t want ego to have to get involved too early,” Blakely added to the School of Hard Knocks in an interview released earlier this week.

Blakely admitted that hearing inevitable negative comments, like “why hasn’t anybody already done it?” or “the big guys will knock you off in six months” would have crushed her dreams—and landed her right back in the career she was trying to escape.

“Had I heard those things the moment that I had the idea, I would probably still be selling fax machines,” the 54-year-old said.

How Blakely built a $1.2 billion empire on ‘unhinged’ behavior

For Blakely, her all-out bet on herself ultimately had massive rewards. 

She grew Spanx over the course of two decades into a brand found in clothing stores around the globe and notably never took any outside investors. When she finally decided to sell in 2021, she reaped the entire $1.2 billion reward—a 240,000x growth on her initial $5,000 investment.

But Blakely hasn’t shied away from being open about fighting tooth and nail to get her business off the ground; As well as keeping it a secret to block out any naysayers, she did whatever it she could within her powers to get the brand noticed.

In her early years, that meant personally going inside Neiman Marcus department stores and moving her product closer to the checkout counter—away from what she called the “sleepiest corner of the store.” And while she admitted it probably wasn’t allowed, it didn’t stop her.

“I always say, ask for forgiveness not permission,” she said.

This self-described “unhinged” behavior didn’t stop there. On her journey to success, she also rode around with a “SPANX” license plate, signed up for British billionaire Richard Branson’s reality TV show, and even paid her friends to go into department stores and buy her product so “it wouldn’t tank.”

“You gotta do what you gotta do,” Blakely wrote on Instagram.