Sometimes I just feel like quitting, but then I think about all the people I’d be letting down.

The past is a kind of future that has already happened.

In times of adversity and change, we really discover who we are and what we're made of.

计算机能否思考的问题就像潜艇能否游泳的问题。

"Think wrongly, if you please, but in all cases, think for yourself."

复杂很容易，简单却很难。