Idiom of the day :- Fight / tilt at windmills

Usage, examples and definition of the Idiom :-

‘Ha, there you are again making threatening gestures at me !’ Aaron cried. ‘I’ll show you that you are not fighting windmills !’ To fight or tilt at windmills is from the novel Don Quixote de la Mancha in which the hero attacks windmills thinking they are giants. The idiom means to struggle against an imaginary opponent or tooppose things that are not important.