Inventor Joy Mangano has sold $3 billion of products and says this is the biggest myth about success

Inventor Joy Mangano has sold more than $3 billion worth of home products. To get to that point, she didn't sell her house or take on a huge loan. She didn't even quit her day job.

Her career-defining moment, a 1992 appearance to showcase her Miracle Mop on QVC, was the result of years of hard work.

In her new book, "Inventing Joy," Mangano says that one of the biggest mistakes people make in their careers is believing that in order follow your dreams, you need to risk everything you have.

"Some people believe that in order to start something new, you have to take drastic actions," she writes. "But that's not true."

"I am of the philosophy that if you work really hard and focus on things, you will get there in some form or fashion," Mangano said in a previous interview with CNBC Make It.

The inventor worked in airline reservations and as a waitress on nights and weekends, as depicted in the movie based on her life "Joy," starring Jennifer Lawrence.

In her spare time, she would work on building a prototype for her self-wringing, compact mop.

"Getting started on the idea didn't change my life all that much," she writes. "I still took my children to school and cooked for them and cleaned up after them."

Mangano's journey has spanned decades. In fact, before receiving the offer to appear on QVC, she tried to sell her product in stores, only to face rejection. So instead, she sold her product in the parking lots of shopping malls.

As a teenager she invented a brightly-colored flea collar for pets that would make them visible to cars at night, Time reports.

While there some entrepreneurs became rich after selling their house or quitting their job, many successful founders tell a different story.

Daymond John, fashion mogul and judge on ABC's "Shark Tank," urges people to not quit their day jobs. Instead, pursue your passion on the side, he says. While he was building his clothing line FUBU, which would grow into a $6 billion brand, he was waited tables at Red Lobster. Giving up your financial stability, he says, is not a wise decision.

According to Mangano, the idea that success means making a huge change to your life isn't only unhelpful, it's limiting.

"There are paths to [following your dream] in a way that is sustainable for us and our families," Mangano writes. "Creativity doesn't have to be all or nothing."

"Believing you have to jump off a cliff is a false impediment," she adds. "There are ways to pursue a life of hope and creativity without risking everything."

If you have an idea but don't know how to start pursuing it, consider the advice of former Google career coach Jenny Blake. She encourages people to follow their career passions in hobbies or meetups.

If you're in an environment where you can pitch new projects or ideas to your boss, suggest a new, manageable assignment for yourself where you get to exercise new skills.

There's a difference between being brave, Mangano says, and being reckless.

"We don't need to do something crazy to get started," she writes. "We just need to believe in ourselves, and take the first small step."

Check out Former Google career coach shares a visual trick for figuring out what to do with your life.

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