The challenge of leadership is to be strong, but not rude; be kind, but not weak; be bold, but not bully; be thoughtful, but not lazy; be humble, but not timid; be proud, but not arrogant; have humor, but without folly.

数学证明的美在于它的简洁性和必然性。

我从不买任何东西，除非我能给出一个充分的理由，说明为什么我认为它会涨。