Learn computer science. It's extraordinarily helpful. I like recommending learning economics as well so they think in terms of business, they have rational frameworks for looking at the world, but yeah, computer science is an amazing way to get into, even if you want to be CEO, having a tech background is helpful.

The most important impact on society and the world is the cell phone. Cell phones have actually been one of the primary drivers in productivity improvements.

I actually think the one who is underestimated in terms of impact he's had on society is Bill Gates. The reason is that with the innovation of software, he really allowed the computer revolution to take hold.

If you're CEO of a company, you have to be a public person. You're speaking to the press, you're speaking to investors, you're speaking to employees, you're the public face of the company and so kind of naturally you become more extroverted, more outwards facing.