‘Shark Tank’ star and self-made millionaire Barbara Corcoran’s advice: ‘Don’t listen to your mother’

In honor of graduation season, CNBC Make It is rolling out the speeches and pieces of advice that America's leaders are most excited to share with the Class of 2017. Follow along using the hashtag #MakeItNewGrads .

Early on, things didn't look great for Barbara Corcoran. She had straight D's in high school and college, and by the time she was 23, she had already failed her way through at least 20 jobs.

Despite these failures, while working as a receptionist for a real estate development company in Manhattan, Corcoran decided she would try her hand renting apartments. In 1973, she borrowed $1000 from her then-boyfriend and opened her own real estate office in New York City.

Corcoran's mother was skeptical of her daughter's entrepreneurial ambitions.

"When I asked my mother if I should start my own business after graduation, she said, 'No!' It was too risky and I was too young!

"She was wrong," says Corcoran. "It made me a millionaire!"

That's why "Don't listen to your mother!" is the advice she'd give to new graduates just about to start their careers, she tells CNBC. People need to believe in themselves and trust their own instincts.

It worked for her. Today, her namesake real estate office, The Corcoran Group, has become a $6 billion dollar business. And she's gone on to become one of the investors on hit ABC reality television show, "Shark Tank."

"Every one of my great successes … they were always the result of an insult," she says.

Look for more exclusive pieces of advice from icons like Melinda Gates, Dave Ramsey and others over the next few weeks. Follow along using the hashtag #MakeItNewGrads .

See also:

Mark Cuban gives his 3 best pieces of advice for college grads

Billionaire investor Chris Sacca's best advice for grads is the same advice he gives himself

Not everyone will believe in you and 5 other lessons Will Ferrell learned on the way to mega success