Deciding what not to do is as important as deciding what to do.
I don't really care what people say about me. I know who I am.
The greatest happiness is to know the source of unhappiness.
数学中最伟大的发现是那些统一看似无关思想的发现。
译文:坏人未必天生就坏,往往是习惯成了本性(梁上君子典故)。