Find that thing you are super passionate about. A lot of founding principles of Facebook are that if people have access to more information and are more connected, it will make the world better; people will have more understanding, more empathy. That’s the guiding principle for me. On hard days, I really just step back, and that’s the thing that keeps me going.

We've changed our internal motto from "Move fast and break things" to "Move fast with stable infrastructure."

Berlin definitely has one of the most vibrant of the startup scenes that I have seen. Not really just across Europe, but across the whole world in terms of cities. It's an interesting dynamic.

If I were starting now I would do things very differently. I didn't know anything. In Silicon Valley, you get this feeling that you have to be out here. But it's not the only place to be. If I were starting now, I would have stayed in Boston. [Silicon Valley] is a little short-term focused and that bothers me.

If you live in an area where there is not a good school, the internet may be the best way to get access to a lot of education material. The same is true if there is not a good doctor - the internet may be the best way to get access to health.

Today we can only hear the voices and witness the imaginations of one-third of the world's people. We are all being robbed of the creativity and potential of the two-thirds of the world not yet online. Tomorrow, if we succeed, the Internet will truly represent everyone.

I know it sounds corny, but I’d love to improve people’s lives, especially socially… Making the world more open is not an overnight thing. It’s a ten-to-fifteen-year thing.