The first rule of any technology used in a business is that automation applied to an efficient operation will magnify the efficiency. The second is that automation applied to an inefficient operation will magnify the inefficiency.

Be nice to nerds. Chances are you'll end up working for one.

I would certainly use my voice to try and avoid anything that undermines confidence, so that parents are using vaccines fully.

A top-quartile teacher will increase the performance of their class - based on test scores - by over 10 percent in a single year. ... That means that if the entire U.S., for two years, had top-quartile teachers, the entire difference between us and Asia would go away.

Vaccination is pretty special because you can do a vaccination campaign anywhere in the world. All you are doing is gathering women from the villages, getting them the vaccines and asking them to go around and find the children.

Like my friend Warren Buffett, I feel particularly lucky to do something every day that I love to do. He calls it "tap dancing to work."

Being maniacal about something is very helpful.