不可一世

    bùkěyīshì

    1. Idiomto consider oneself unexcelled in the world; to be insufferably arrogant (idiom)

    他年轻时不可一世,后来才明白自己有多渺小。Tā niánqīng shí bùkěyīshì, hòulái cái míngbai zìjǐ yǒu duō miǎoxiǎo.In his youth, he was insufferably arrogant, only to later realize how insignificant he truly was.