You likely have never heard of Joe Green; we didn't know him. In some alternate universe though, we may have been very familiar with the Harvard grad.
Green was one of Facebook founder, Mark Zuckerberg, roommates at school in 2004. Zuckerberg, now worth around $17.5 billion, invited Green to drop out with him to join the social network.
Green declined after boiling in hot water for their 'hot-or-not' experiment, the building block of today's Facebook, that year. Today, that negative has cost Green around $400 million.
"We'd gotten into a little bit trouble with the previous project ... and my father, who's a professor, was not too happy with the prospect of me getting kicked out of school," Green told ABC News. "Zuckerberg likes to make fun of my dad for this, but we're still very close."
He still remains active in the Facebook community, promoting his charity facilitator 'Causes'.