鱼相忘乎江湖，人相忘乎道术。
鱼儿在江湖中彼此相忘，人在道术中彼此相忘。
Today is cruel, tomorrow is crueler, and the day after tomorrow is beautiful, but most people will die tomorrow night, so don't give up today.
The fountain of content must spring up in the mind, and they who have so little knowledge of human nature as to seek happiness by changing anything but their own dispositions will waste their lives in fruitless efforts.
The only real voyage of discovery consists not in seeking new landscapes, but in having new eyes.