The PC has improved the world in just about every area you can think of. Amazing developments in communications, collaboration and efficiencies. New kinds of entertainment and social media. Access to information and the ability to give a voice people who would never have been heard.

I understand how every healthy child, every new road, puts a country on a better path, but instability and war will arise from time to time, and I'm not an expert on how you get out of those things.

I'm invested in a lot of battery companies - and there's a lot that exists I'm not in.

The interview process tests not what the applicant knows, but how well they can process tricky questions: If you wanted to figure out how many times on average you would have to flip the pages of the Manhattan phone book to find a specific name, how would you approach the problem? If a spider fell to the bottom of a 50-foot well, and each day climbed up 3 feet and slipped back 2, how many days would it take the spider to get out of the well? .

In K-12, almost everybody goes to local schools. Universities are a bit different because kids actually do pick the university. The bizarre thing, though, is that the merit of university is actually how good the students going in are: the SAT scores of the kids going in.

AIDS itself is subject to incredible stigma.

When making choices, or setting policies about the economy, education or medicine, society is best served by electing people who are particularly hardworking, intelligent and interested in long-term thinking.