Mark Zuckerberg, founder of Facebook has returned to Harvard to pick up his degree 12 years after dropping out to work full-time on Facebook.

Mark founded what was then called “The Facebook” in 2004 in his college dormitory. The Facebook was at first limited to only Harvard students before later expanding to other Ivy League universities.

Delivering the commencement address – a speech given to graduating students –  to the 2017 graduating students on Thursday, he said, “It’s good to be idealistic. But be prepared to be misunderstood. Anyone working on a big vision will get called crazy, even if you end up right. Anyone working on a complex problem will get blamed for not fully understanding the challenge, even though it’s impossible to know everything upfront. Anyone taking initiative will get criticized for moving too fast, because there’s always someone who wants to slow you down.”

“In our society, we often don’t do big things because we’re so afraid of making mistakes that we ignore all the things wrong today if we do nothing. The reality is, anything we do will have issues in the future. But that can’t keep us from starting.”

Whiles in Harvard he returned to the room where he started building Facebook with his co-founders Dustin Moskovitz, Eduardo Saverin, Andrew McCollum and Chris Hughes.

Mark Zuckerberg is one of the university dropouts who became millionaires after founding tech companies like Bill Gates and Steve Job. But unlike Mark who went back to Harvard for his degree after 12 years, Bill Gates received his honorary degree in 2007 after dropping out to start Microsoft in 1975.