This is a perverse thing, personally, but I would rather be in the cycle where people are underestimating us. It gives us latitude to go out and make big bets that excite and amaze people.

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.

Move fast and break things. Unless you are breaking stuff, you are not moving fast enough.

People don't care about what someone says about you in a movie--or even what you say, right? They care about what you build.

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.

Facebook was not originally created to be a company. It was built to accomplish a social mission - to make the world more open and connected.

In a world that's changing so quickly, you're guaranteed to fail if you don't take any risks.