无wú忧yōu无wú虑lǜ

Literal: no worry, no care
Figurative: Carefree and free of worries; living at ease without anything weighing on your mind.

Where does 无忧无虑 come from?

It is not a tale with a moral but a literary expression whose earliest documented appearance is in Yuan-dynasty drama: the play "Renzi ji" (忍字记) by Zheng Tingyu (郑廷玉), whose second act reads "做了个草庵中无忧无虑的僧家" ("I have become a monk without sorrows or cares in his hermitage"). It is built on the parallel pattern 无…无… ("without… without…"), repeating 无 before 忧 "sorrow" and 虑 "worry." Since then it has described a state of mind free of burdens, especially that of children or of a life without strain.

Source (出处): 《忍字记》

How is 无忧无虑 used? Two examples

小xiǎo时shí候hou我wǒ们men无wú忧yōu无wú虑lǜ，每měi天tiān只zhǐ想xiǎng着zhe出chū去qù玩wán。
As children we were carefree, and every day all we thought about was going out to play.
退tuì休xiū以yǐ后hòu，他tā过guò着zhe无wú忧yōu无wú虑lǜ的de生shēng活huó。
After retiring, he leads a carefree life.

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