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.