Berlin is one of my favorite cities in the world. I feel like the energy is very youthful. It has such an important history, including its recent history of unification.

I personally don't invest in a lot of companies because I think it would be a conflict of interest and Facebook doesn't typically either.

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

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

In a recent survive of Millennials around the world asking what most defines our identity, the most popular wasn't nationality, ethnicity or religion. It was "citizen of the world." That's a big deal. Every generation expands the circle of people we consider one of us. And in our generation, that now includes the whole world. This is the struggle of our time. The forces of freedom, openness, and global community against the forces of authoritarianism, isolationism, and nationalism - forces for the flow of knowledge, trade, and immigration, against those who would slow them down.

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.

There are many machines throughout history that were built to do something better than a human can.