Self-Made Millionaire David Castain Speaks at Harvard UniversitySerial entrepreneur David Castain has joined the ranks of people like Mark Zuckerberg, Oprah Winfrey, and Bill Gates speaking at Harvard University.

"Someone's inability to believe your dream does not make them invincible.

If there is one in a million shots, take it, because that means there is a possibility," he told the students.

The occasion was sponsored by leading global investment bank Morgan Stanley and organized by The Harvard European Business Group, The Key Society and Forbes8, a new community powered by Forbes.Harvard graduate Zena Edosomwan said, "This event could not have come at a better time.

I wanted to give students real-life examples of how others forged their own ways, despite criticism or traditional expectations."

Zena is Co-founder of They Key Society, a company that created a shared community for students from Harvard, Yale, Stanford, MIT and Princeton.