Don't do unto others what you don't want others to do unto you.

The hardest thing of all is to find a black cat in a dark room, especially if there is no cat.

The Master said, “What a worthy man was Yan Hui! Living in a narrow alley, subsisting upon meager bits of rice and water—other people could not have borne such hardship, and yet it never spoiled Hui’s joy. What a worthy man was Hui!” (Analects 6.11)

Never do to others what you would not like them to do to you.

Thought, unassisted by learning, is dangerous.

Knowing something is not as good as liking it. Liking something is not as good as rejoicing in it.

Learning, undigested by thought, is labor lost.