Microsoft has had many, many successful products. I'm committed to one company. This is the industry I've decided to work in.

Should surveillance be usable for petty crimes like jaywalking or minor drug possession? Or is there a higher threshold for certain information? Those aren't easy questions.

Cutting through complexity to find a solution runs through four predictable stages: determine a goal, find the highest-leverage approach, discover the ideal technology for that approach, and in the meantime, make the smartest application of the technology that you already have - whether it's something sophisticated, like a drug, or something simpler, like a bednet.

As you improve health in a society, population growth goes down. You know, I thought it was... before I learned about it, I thought it was paradoxical.

'I don't know' has become 'I don't know yet'.

So we do software for watches, for phones, for TV sets, for cars. And some of these take a long time to catch on.

Talking to mothers, always brings it home because they're so anxious to do everything they can for their kids and so tragic for them.