一个好的抽象是捕捉概念的本质方面，同时忽略无关的细节。

成功的真正标准是让土地比我们发现时更好。

The consequences of this problem make themselves felt in bookshops. When you go to a large bookshop and look at the self-help sections, as I sometimes do -- if you analyze self-help book sproduced in the world today, there are basically two kinds. The first kind tells you, "You can do it! You can make it! Anything's possible!" The other kind tells you how to cope with what we politely call "low self-esteem," or impolitely call, "feeling very bad about yourself."