世事

shì shì duō biàn

世事多变

the world is always in flux

bǎo jīng shì shì

饱经世事

have experienced many vicissitudes of life

bù ān shì shì

不谙世事

be unhackneyed and unpractised in the ways of the world

shì shì ràng sān fēn tiān kuān dì kuò

世事让三分，天宽地阔。

Give in a little, and the world will become bigger for you.

shì shì dòng míng jiē xué wèn rén qíng liàn dá jí wén zhāng

世事洞明皆学问，人情练达即文章。

A grasp of mundane affairs is genuine knowledge.