From the October 2003 issue of Entrepreneur

You're ready to start your day, go into that important meeting or call on a high-level prospect. You've done your homework; you're prepared. And then you hear it: that voice inside your head that says "You're not cut out for this," or "You can't make a sale this way. It's just not the way it's done!"

It's a voice that comes from doubters and naysayers who undermine our confidence and tell us, in subtle and blatant ways, that we cannot accomplish our dreams, or that the only way to succeed is to follow the path of "what has worked before." In reality, that path leads nowhere. If you really want to succeed, you must win the battle within yourself and tell those voices to pack up, hit the road, and take their unwanted opinions with them. It's not always easy to kick them to the curb, but here are three effective ways to get started:

1. Look to the history books. History is filled with stories of people who overcame the odds to achieve greatness. Madame Curie, Thomas Edison, Albert Einstein, Henry Ford, Martin Luther King Jr.--all had to stand up to people around them and say "I can do this, whether you think so or not." Most of us think courage only applies to saving someone's life or showing bravery in extreme circumstances. But if you struggle each day to overcome adversities large and small, like we all do, you show a great amount of courage when you press on instead of giving up.

2. Learn to fall the right way. As salespeople, we get knocked down all the time. Rejection comes with the territory. That's when those voices start shouting "I told you so!" But the courage to sell is to look at the circumstance and say "Was there something I could have done differently?" If the answer is yes, then you can go back and resell a different way or learn from your mistake so that you don't repeat it with the next customer.

3. Don't be afraid to try something new. The uncommon path is blocked by common thoughts of disapproval. People will tell you "You can't call on people at this level in our industry," or "This person never takes cold calls." Everyone has his or her own rules, and most will steer you down the usual trail. Sure, some people have valuable insights to impart, and what they say should become part of your knowledge base. But the real test comes only through action-when you actually make that call, close that deal, bring in a new product idea, call on that next level, introduce a new partner, or come up with innovative win-win solutions.

So don't give up or let those voices hold you back anymore. Born of fear and a lack of confidence, they can be vanquished with courage, persistence and experience.