Shark Tank's Barbara Corcoran: 4 Things Successful Entrepreneurs Do The 'Shark Tank' investor and real estate mogul discusses the necessity of extreme optimism and why logic can be dangerous

For all her success, Barbara Corcoran is no stranger to failure. She may be riding high at the moment -- a star investor on ABC's hit show Shark Tank with a $5 billion real estate business -- but Corcoran is the first to admit that it took her awhile to get here.

She doesn't hide her succession of strikeouts; instead, she celebrates them, prominently advertising on her website that she had 20 jobs before she turned 23.

That's because for Corcoran, success and failure are irrevocably linked. The single most important quality every entrepreneur needs in order to succeed, she says, is the ability to fail well. "You have to be great at handling rejection, and then more rejection, and then still more rejection."

From personal experience, she understands that when you're starting out, negative feedback will always outweigh any form of encouragement. "You have to regroup really fast and get back up; otherwise the business will never be born. It's like pushing out a baby," she laughs. "Just keep pushing until eventually, you have yourself a business."

Unsurprisingly, not everyone is cut out of durable entrepreneurial cloth, which is part of what inspired Corcoran to offer an online course through global learning community Skillshare entitled The Fundamentals of Entrepreneurship: Pitching Your Business and Yourself. "My goal with this series is to either push someone off the fence or tell them to keep their day job," she says. By the end of the eight-class series "there should be no doubt in anyone's head about whether or not they will make a good entrepreneur."

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With Corcoran's first class kicking off today, she shared with Entrepreneur.com her views on what it takes to make it as an entrepreneur.

1. Cultivate irrational optimism. If you want to strike out on your own, you're going to have to be optimistic to the point that exceeds all logic, says Corcoran. "You have to see everything as half-full even though everyone is saying you have nothing in your glass." Rational analysis has its place, but for a budding entrepreneur, it can be dangerous. Starting out, "You almost need to have a low IQ," Corcoran says. To succeed as an entrepreneur, optimism is often more important than intelligence.

2. Embrace your fears by confronting them. One of Corcoran's most memorable failures involved a common fear: public speaking. She lost her voice when she was giving her first presentation, and was mortified.

Placed in the same situation, many people would (understandably) react by avoiding speaking in front of an audience at all costs. Corcoran, instead, volunteered to teach a real estate night course at NYU.

"I had two choices: I could stay in the rabbit hole and be ashamed and embarrassed or I could learn how to do it," she remembers. She figured that getting in front of a small group of students was the perfect environment to sharpen her oratory skills. It turned out to be an incredibly fortuitous decision; not only did her public speaking improve, but one of her students, Carrie Chiang, turned out to an amazing salesperson. Corcoran recruited her, and Chiang remains one of the top brokers in New York City.

Corcoran has found that it's usually works out like this. "Every single failure has an equally great upside if you are willing to stay in the game," she says. "If I hadn't failed at that speech, I would have not been teaching that course to get over my fear of public speaking," and she would never have discovered Chiang. But that doesn't happen if you throw your hand up and walk away from the game. "You can get hit hard, you come back hard and you always get rewarded."

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3. Fake it until it's real. While many successful entrepreneurs (including some of her fellow "Shark" investors) project a blustery confidence, Corcoran admits that she battles insecurity on a daily basis. Instead of trying to eliminate self-doubt, however, she recommends using insecurity as a motivator. "It gets you to try harder because you don't want to get caught. You work so hard to look the part that soon, without even realizing it, you are the part."

But how do you project a confidence façade when you're feeling inadequate on the inside? Corcoran finds that women struggle with this far more than their male counterparts, so her solution is often to simply ask herself: What would a man do? "If I ask myself that, my hand goes up. If I ask myself that, I take credit right away, "she says. "I cheerlead myself. I think, 'You have just as much right as that guy to be here, you have the right to be as rich as he is, this isn't a frat boys-club'; I get arrogant in my head – hopefully I don't act arrogant on the outside-- but that arrogance pushes me forward."

4. Leap first, think later. This ties back to Corcoran's point that sometimes, logic can hurt an entrepreneur more than it helps her. "If you stand back and analyze the best way to do something, you'll be standing there forever," she says. Corcoran doesn't subscribe to the philosophy that there is a 'right time' to expand a business. Instead, she recommends getting that bigger office. Today. Because if you hold back, waiting until every variable is in place, it will never happen.

In addition, operating out of an office that's too big for your company creates pressure to fill the space and pressure is important. "You're always smarter under fire than you are standing on the outside assessing a situation," she says. "You can't study to be an entrepreneur. Sometimes, you just have to jump."