Trust is a confusing thing. It seems so simple, but when you try to pin it down, it can be so elusive.

On street corners everywhere, people are looking at their cell phones, and it's easy to dismiss this as some sort of bad trend in human culture. But the truth is life is being lived there. When they smile - right, you've seen people stop - all of a sudden, life is being lived there, somewhere up in that weird, dense network.

I studied neuroscience at the cellular level, so I was looking at learning and memory in the visual cortex of rats. Neuroscience mainly exposed me to a way of thinking - about experimentation, about what you believe to be true and how you could prove it - and how to approach things in a methodical manner.

I've been fascinated by the Internet from the very start. In 2001, I had made a funny black-and-white film called 'How to Dance Properly,' a short video of me dancing to a Madonna song. I sent it to 17 of my friends on a Thursday, and by Monday, one million people a day were logging on to view it.