我不断看到有些人在生活中越过越好，他们不是最聪明的，甚至不是最勤奋的，但他们是学习机器。他们每天夜里睡觉时都比那天早晨聪明一点点。

The great secret that all old people share is that you really haven't changed in seventy or eighty years. Your body changes, but you don't change at all. And that, of course, causes great confusion.

可持续性不仅仅是一个流行词，更是我们对后代的责任。