A great biography is a kind of pilgrimage, walking in someone else’s footsteps while trying to understand their soul.

Causal inference is not just about statistical significance; it's about understanding the mechanisms behind the numbers.

We want to build technology that everybody loves using, and that affects everyone. We want to create beautiful, intuitive services and technologies that are so incredibly useful that people use them twice a day. Like they use a toothbrush. There aren’t that many things people use twice a day.

最伟大的定理往往始于简单的猜想，源于直觉。