Entrepreneurs are risk takers because they don't think about the odds. They are constantly diving into new business opportunities - they don't care what other people say or think about their ideas. If everyone always listened to the non-believers, we wouldn't have airplanes or IPods. Entrepreneurs are the ones that really make the world different.
Anyone can become an entrepreneur. It's easy to come up with business ideas - putting those ideas to action is the important part. If you have an awesome business idea in mind that you believe in, then go for it. Seriously, if you don't try, then you're just another dreamer.
When two young men just out of college - Nick Friedman and Omar Soliman - came up with the idea to start College Hunks Hauling Junk (a junk-removal service), they were criticized and laughed at. People thought the idea was stupid and tried to talk them out of it. But did they give up? Nope. Their business stands today as a multi-million dollar company and they are constantly looking into expanding their business even further to make more money.
So when you come up with an idea, immediately take action on it. This means buying the business cards, registering the domain, and coming up with a plan to get yourself in business. Figure out why your idea stands out from the rest and use that as part of your sales pitch.
You can't accomplish anything without taking step #1. Go for it.