If you focus on near-term growth above all else, you miss the most important question you should be asking: will this business still be around a decade from now?

I think somehow people should be encouraged to think about a very long time horizon and I think this is true for businesses, it's true for governments and it's true for people doing things in the non-profit sector.

We cannot take for granted that the future will be better, and that means we need to work to create it today.

Every university…seem[s] to reassure you that ‘it doesn’t matter what you do, as long as you do it well.’ That is completely false. It does matter what you do. You should focus relentlessly at something you’re good at doing, but before that you must think hard about whether it will be valuable in the future.

A true bubble is when something is overvalued and intensely believed.

Technology is probably the single biggest driver of productivity gains for the developed countries. For example, I think it's much more important than free trade.

Twitter is hard to evaluate. They have a lot of potential. It's a horribly mismanaged company — probably a lot of pot-smoking going on there. But it's such a solid franchise it may even work with all that.