Robots will play an important role in providing physical assistance and even companionship for the elderly.

It is a high bar to say that it's more fun than working on software because the work at Microsoft that both Melinda [Gates] and I did was thrilling. We were making breakthroughs and empowering people.

We are always saying to ourself.. we have to innovate. We got to come up with that breakthrough... we're only paid for breakthroughs.

I like the idea of putting your Christmas wish list up and letting people share it.

I went public too soon. Stay private as long as you can.

Now, we put out a lot of carbon dioxide every year, over 26 billion tons. For each American, it's about 20 tons. For people in poor countries, it's less than one ton. It's an average of about five tons for everyone on the planet. And, somehow, we have to make changes that will bring that down to zero.

Scientists and companies weren't creating things like new vaccines. Now that we have this fund that's there to buy at the lowest price, but buy for those people these medicines, we see scientists everywhere coming up with those new tools.