There is no rule without exception.—Cervantes
有規則必有例外。《西萬提斯》

A friend in need is a friend indeed.
患難之交才是真心的朋友。

If you are going to be a bridge, got to be prepared to be walked upon.
假如你想成為橋樑，就要有被踐踏的準備。

Start with what is right rather than what is acceptable.
從正確的事開始做，不要從可接受的事情開始做。
《彼得。杜拉克 Peter F. Drucker 美國管理作家與管理顧問》

Temptation usually comes in through a door that has deliberately been left open.

誘惑之所以得其門而入，皆因門是故意開的。