You must believe in yourself as an entrepreneur before anyone else will take you seriously. But what if it doesn't come naturally? Can you train yourself to believe in your ultimate success?

The answer is yes. The successful among us are often iconoclasts. Playwright George Bernard Shaw put it best a century ago: "The reasonable man adapts himself to the world; the unreasonable man persists in trying to adapt the world to himself. Therefore all progress depends on the unreasonable man."

So how do you become constructively "unreasonable?"

Last time, we wrote about six key ways to convince stakeholders that you're the real deal. Based on our study of hundreds of successful entrepreneurs, here are five key ways to train yourself to believe in your ultimate success.

1. Develop relationships with other entrepreneurs. Having peers and mentors matters. So ask yourself: “Who’s really got my back?” Surround yourself with smart, enthusiastic people-- and build a support system of others who strive to be exceptional. Meanwhile, why not work for proven entrepreneurs? What better way to learn how they think?

2. Manage fear proactively. Neuroscience tells us that our brains still run an operating system from back in the caveman days, and fear is a big part of it.  The most effective way to overcome trepidation is to expose yourself gradually to the object of your dread, which can make it all seem less potent. Fear never goes away completely, but you can learn to channel fear it as a motivation instead of an excuse for inaction.

3. Celebrate the positive. Much of life's experience depends on your attitude. So, here's an exercise: Sit down and write out a dozen instances when you've been successful in life in any context. Did you get an A in the hardest class in college?  Did you convince the girl or boy of your dreams to date or even marry you?  Write it out-- and develop a reservoir of confidence.

4. Listen to customers. The customer is your compass. Listen actively to the market to learn about what customers want today-- but also what they’re likely to want by the time you can deliver solutions. You'll always have more valid reasons to believe in your ultimate success if you can consistently say you've developed your venture to meet specific customer needs.

5. Seek and find external validation. Many successful people talk about simple, fateful moments when others validated their ambitions. A century ago, Henry Ford cited brief words of encouragement from Thomas Edison that bolstered his confidence. To be effective, validation has to come from someone you view as admirable and credible, and it should come after you've taken steps toward your goal.  You want to believe that the person validating your efforts knows what he’s talking about---but also that you do, too.