解释：不可以不知道活着的乐趣，也不可以不知道虚度光阴的担忧。

历史的重量由那些记得的人承担。

Stay hungry, stay foolish.

The choice for mankind lies between freedom and happiness and for the great bulk of mankind, happiness is better.

Leadership means making tough decisions today to ensure a better tomorrow.

Sustainability isn't a trend—it's a responsibility we owe to future generations.