海中捞月 fishing for the moon in the sea
Explanation
比喻徒劳无功，白费力气。
It is a metaphor for fruitless effort and wasted energy.
Origin Story
从前，有一个书生，他勤奋好学，为了考取功名，夜以继日地读书。有一天，他读累了，便走到窗前，望向远方，看见一轮明月高悬于夜空。他突然想起了一个问题：月亮是否真的在水中？于是，他跑到井边，对着井水，寻找月亮的倒影。他久久地寻找，却始终找不到，最后，他无奈地叹了口气，心想：这就像是在海里捞月亮一样，永远也捞不到。于是他放弃了。
Once upon a time, there was a scholar who was diligent and studious. In order to achieve fame and glory, he studied day and night. One day, after reading for a long time, he went to the window, looking towards the distant horizon, and saw a bright moon hanging high in the night sky. He suddenly remembered a question: Is the moon really in the water? So, he ran to the well and looked into the water, searching for the reflection of the moon. He searched for a long time, but he couldn't find it, and eventually let out a disappointed sigh, and said to himself, this is just like trying to fish the moon from the sea; it can't be done.
Usage
多用于形容事情难以成功，或努力没有结果。
Often used to describe something that cannot succeed or that effort does not lead to success.
Examples
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他为了寻找丢失的钱包，到处乱翻，简直是海中捞月。
tā wèile xúnzhǎo dīshi de qiánbāo, dàochù luànfān, jiǎnzhí shì hǎi zhōng lāo yuè
He searched everywhere for his lost wallet; it was like searching for the moon in the sea.
-
你这样毫无计划地找工作，就像海中捞月，徒劳无功。
nǐ zhèyàng háo wú jìhuà de zhǎo gōngzuò, jiù xiàng hǎi zhōng lāo yuè, túláo wúgōng
Your aimless job search is like fishing for the moon in the sea - in vain!