If you just work on stuff that you like and you're passionate about, you don't have to have a master plan with how things will play out.

AI systems will enable doctors to diagnose diseases and treat people better, so blocking that progress is probably one of the worst things you can do for making the world better.

If you actually do something you love it's a lot easier and takes on a lot more purpose.

Facebook is inherently viral.

Right now, with social networks and other tools on the Internet, all of these 500 million people have a way to say what they're thinking and have their voice be heard.

I hope that Facebook and other Internet technologies were able to help people, just like we hope that we help them communicate and organize and do whatever they want to every single day, but I don't pretend that if Facebook didn't exist, that this wouldn't even be possible. Of course, it would have.

When you want to change things, you can't please everyone. If you do please everyone, you aren't making enough progress.