I like to pride myself on thinking pretty long term, but not that long term.

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

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

Think about what people are doing on Facebook today. They're keeping up with their friends and family, but they're also building an image and identity for themselves, which in a sense is their brand. They're connecting with the audience that they want to connect to. It's almost a disadvantage if you're not on it now.

More than four million businesses have Pages on Facebook that they use to have a dialogue with their customers.

Don't discount yourself, no matter what you're doing. Everyone has a unique perspective that they can bring to the world.

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.