世态炎凉别太善良人间冷暖别太手软
[shì tài yán liáng bié tài shàn liáng rén jiān lĕng nuăn bié tài shŏu ruăn]
'The world is indifferent and unfriendly. Don't be too kind, and don't be too reluctant to do what is necessary. There are many ups and downs in the world, you cannot be too merciful or too lenient with people.'