Do you think that dropping out of college to start a business is a risk? Are you a risk taker? Would you drop out of college to start a business? Bill Gates did. He dropped out of Harvard to start Microsoft, which became one of the most innovative companies ever. He's like many self-made billionaires and entrepreneurs; he is a risk-taker and an innovator (actually, that also describes many self-made millionaires).

Risk tolerance and innovation are just two of the personality characteristics of self-made billionaires. Here are more:

• They are entrepreneurial
• They "step up to the plate" when an opportunity arises
• They see opportunity where nobody else does
• They don't procrastinate, they "make it happen"
• They are full of optimism
• They accept mistakes because there is an opportunity to learn from failure
• They enjoy success and thrive to achieve it
• They appreciate their own personal success
• They are motivated
• They know how to invest
• They make money doing things that they love
• They practice time-management, meaning they dont waste their time on meaningless tasks
• They are influential and persuasive
• They surround themselves with smart people
• They have business sense
• They are fearless
• They are intelligent

Of course, these are just some of the common characteristics of self-made billionaires. Not all self-made billionaires carry these traits but all have an incredible desire to succeed and most could do it all over again if they lost it all.