After building the world's largest social network and becoming one of the richest people on the planet, it's hard to believe that Facebook's CEO Mark Zuckerberg is only turning 28 today. At half the age of the average S&P 500 CEO, Zuckerberg has accomplished more than his contemporaries and even some of his idols. The company he founded in his Harvard dorm room is set to go public this Friday with an IPO that could value the company at $100 billion. 

Despite the fact that he still rocks hoodies and t-shirts to all his meetings and informed future investors that he cares more about making a good product using "the hacker way" over making money, Zuckerberg has grown up a lot since Facebook launched in 2004. He's also done some pretty awesome badass things. Since everyone's focusing on the former, we decided to focus on the latter. Happy Birthday, Zuck!