Billionaires are successful because they're nonconformists with individualist tendencies, according to Rafael Badziag in his book "The Billion Dollar Secret." This strength is also their weakness, Badziag said — billionaires shouldn't favor individualism over cooperation. Billionaires also shouldn't avoid asking for help or advice, as those kinds of tendencies can become a major limitation. Visit Business Insider's homepage for more stories. Sometimes strengths and weaknesses can look a whole lot alike. Just take a look at billionaires.