When self-delusion and self-flattery enter the mind-set of a product team and the metrics they judge themselves by, like the first plague rat coming onto a ship, the end is practically preordained.

In Silicon Valley, where I worked at companies like Facebook and Twitter for the earlier part of this decade, Cuba was generally regarded, when it was regarded at all, as a technological curiosity.

If the world really does end, there aren't going to be many places to run.

If you'd come to me in 2012, when the last presidential election was raging and we were cooking up ever more complicated ways to monetize Facebook data, and told me that Russian agents in the Kremlin's employ would be buying Facebook ads to subvert American democracy, I'd have asked where your tin-foil hat was.

I think it's one of the challenges of modern politics, which is, how do you communicate who the candidate is, and what they really believe, in the short time period you have? And for me, the best opportunity was the debates, and I think I was in real trouble before the debates, and I think the debates helped me a lot.

The world changes materially. Science makes advances in technology and understanding. But the world of humanity doesn't change.

The American political system is based on the president taking the initiative and Congress responding. With President Trump, it's been the opposite.

People who wave digital cameras at shows are the same people who sit in front of you at hockey games and wear those giant foam-rubber fingers that say, We're number one!'