Openness fundamentally affects a lot of the core institutions in society - the media, the economy, how people relate to the government and just their leadership.

If the original Facebook was the first five minutes [of a conversation] and the stream was the next 15, what I want to show you today is the rest-the next few hours of a deep engaging conversation.

I actually remember very specifically the night that I launched Facebook at Harvard. I used to go out to get pizza with a friend who I did all my computer science homework with. And I remember talking to him and saying I am so happy we have this at Harvard because now our community can be connected but one day someone is going to build this for the world.

If a product costs $10,000 or $20,000 it has limited use. This is what the first computers cost! Only when almost everyone is able to afford it will it be a real thing.

We have a pretty ambitious goal for the world. What we think will make the Web better. What we think will make all these businesses that integrate with us run more effectively. I think if we stay focused on doing that, that's really the main thing that we need to do.

It only took me two weeks to build the first version of Facebook because I had so much stuff before then.

Why are most chess masters under 30?