An entrepreneur must deal with more uncertainty than a professional with a well-defined role.

When I was starting out, I followed along the path that seemed to be marked out for me - from high school to college to law school to professional life.

People don't want to believe that technology is broken. Pharmaceuticals, robotics, artificial intelligence, nanotechnology - all these areas where the progress has been a lot more limited than people think. And the question is why.

Credentials are critical if you want to do something professional. If you want to become a doctor or lawyer or teacher or professor, there is a credentialing process. But there are a lot of other things where it's not clear they're that important.

A friend is an emotional bond, just like friendship is a human experience.

I think that talking about the personal specificity, personal details, is how you get the big, big audiences - by talking about your relationships or your personal tragedies. If you reach out with that energy, you'll touch people.

In the world of online invitations, nothing is sacred. People will invite all 500 of their 'closest' friends to their birthday party - and 485 of those people will RSVP 'yes' without intending to show up.

I'm torn about late parenting. I believe people should spend their twenties living and having fun and not having any regrets later. I also think people in their thirties generally make better parents but so many of my friends are having trouble - myself included - as fathers get older.