年轻时的我很无知，总以为自己什么都懂。

Niánqīng shí de wǒ hěn wúzhī, zǒng yǐwéi zìjǐ shénme dōu dǒng.

When I was young, I was very ignorant and always thought I knew everything.

嘲笑别人的无知并不能证明你聪明，只会显得没有礼貌。

Cháoxiào biérén de wúzhī bìng bù néng zhèngmíng nǐ cōngmíng, zhǐ huì xiǎnde méi yǒu lǐmào.

Laughing at others’ ignorance doesn’t prove you are smart; it only makes you look impolite.

他因为无知而做出了错误的决定。

Tā yīnwèi wúzhī ér zuòchū le cuòwù de juédìng.

He made the wrong decision because of his ignorance.