On ABC's "Shark Tank," Kevin O'Leary is famous for giving aspiring entrepreneurs his honest opinion, even when it's hard to hear. And according to O'Leary, his own stepfather gave him some tough love that ultimately influenced his future success.
When O'Leary was young, he wanted to be a musician (he played the guitar), an artist or a photographer, he says. But his stepfather had some harsh advice.
"He looked me in the eye after I finished high school and said, 'You're not good enough at any of those. And you might as well face the reality now that you're going to starve to death if you pursue them,'" O'Leary tells CNBC Make It. "You're not the best photographer out there. You're not even the best guitarist. So how are you going to become No.1 in a space where you're starting at a negative six?'"
At, first O'Leary thought maybe he could just get better at those things. But his stepfather encouraged him to explore other career paths that might be a better fit.
"He said, 'How about this? How about you go back and figure out what you're good at? And I think you're a good marketer. You work hard. You hustle. Maybe you should pursue a business career,'" O'Leary says. "He was 100% right."
O'Leary went on to get an MBA from the Ivey Business School at Western University in Ontario. Then he founded a sports programming production company.
"It's kind of interesting because I wanted to get back at him a little bit — and that's kind of a relationship you have with fathers and stepfathers," O'Leary says. "So what did I start? I started a film production company, where I could take pictures all day long. And it worked."
Ultimately, O'Leary went on to become a business mogul. In 1986, he started Softkey Software Products in his basement with no cash, building it into a booming business that sold to Mattel Toy Company in 1999 for a reported $4.2 billion. Now in addition to "Shark Tank," O'Leary runs a number of other ventures he founded, like investment fund company O'Leary Funds and O'Leary Fine Wines.
But just because he's been successful in business, doesn't mean that O'Leary has abandoned his love of the arts. In fact, he says the best part about his success in entrepreneurship is that it has given him the freedom to spend time on his passions, like photography. O'Leary says he now has a massive collection of cameras and lenses and does film editing for his existing businesses as part of his Sunday routine.
And O'Leary credits his stepfather with giving him the honest feedback that ultimately set him up for a successful career.
"Sometimes it's very sobering when a parent tells you you're not good at something," O'Leary says. "You have to look at it this way: You know they love you. They want the best for you, but they want you to deal in the truth. In life, it's so important to face reality straight on. The worst thing you can do for yourself is to fool your own self about your potential and your future.
"He was trying to be kind to me by saying, 'No, you're not gonna be a rock star. No, you're not gonna be a photographer. Neither of those are going to work. You've got to be in business, make some money and then pursue the things you like,'" O'Leary adds. "Which I eventually did."
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Disclosure: CNBC owns the exclusive off-network cable rights to ABC's "Shark Tank."