Chinese idiom for "tilt at windmills" or "fighting against windmills" Is there a Chinese idiom for &quot;tilting at windmills&quot;?
This expressions stems from &quot;The Ingenious Gentleman Don Quixote of La Mancha&quot;. In that book, Don Quixote attacks windmills, incorrectly (and absurdly) believing them to be giants.
From Wikipedia:

Tilting at windmills is an English idiom which means attacking imaginary enemies. The word “tilt”, in this context, comes from jousting.
The phrase is sometimes used to describe confrontations where adversaries are incorrectly perceived, or to courses of action that are based on misinterpreted or misapplied heroic, romantic, or idealistic justifications. It may also connote an importune, unfounded and vain effort against confabulated adversaries for a vain goal.
The closest I can find is 水中捞月 (shuǐ zhōng lāo yuè). From 汉典:


  到水中去捞月亮。比喻去做根本做不到的事情，只能白费力气。


Trying to scoop up the imaginary moon from its reflection in the water. That is, trying to do something in vain or making a futile effort.

If you want to emphasize on the physical effort, 以卵击石 (yǐ luǎn jī shí) might be better:


  拿蛋去碰石头。比喻不估计自己的力量，自取灭亡。


Using an egg to hit the stone. Overestimating one's ability and courting certain "death". The death here usually refers to failure.

I am not sure if you will be able to find an idiom that matches all the characteristics in the English idiom.