Just because you can build a machine that is better than a person at something doesn't mean that it is going to have the ability to learn new domains or connect different types of information or context to do superhuman things. This is critically important to appreciate.

Our strategy is very horizontal. We're trying to build a social layer for everything. Basically we're trying to make it so that every app everywhere can be social whether it's on the web, or mobile, or other devices.

Building a mission and building a business go hand in hand.

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.

Simply put: we don't build services to make money; we make money to build better services.

If you want to be free, or you want to preserve freedom for people, you both need to have laws that make it so people have freedom of speech and all the freedoms that they need. You also need to have an open governance system where people can vote and people have representation.

In a lot of ways Berlin is a symbol for me of Facebook's mission: bringing people together, connecting people and breaking down boundaries.