乐观主义者认为这是所有可能世界中最好的一个。悲观主义者则担心这是真的。

"Books are the quietest and most constant of friends; they are the most accessible and wisest of counselors."

我只与自己竞争。我的目标是比昨天的自己更好。

The limits of the possible can only be defined by going beyond them into the impossible.

I can't understand why people are frightened of new ideas. I'm frightened of the old ones.