At last - today's word today! Mull-over-March "Wind/Kite"
I heard this expression years ago when my friend was accused of "Tilting at Windmills" by his mother.
It is apparently an English idiom which means attacking imaginary enemies. The word "tilt" in this context comes from jousting.
Wikipedia (I know!) tells me that the phrase derives from an episode in the novel "Don Quixote". In the novel Don Quixote fights windmills that he imagines are giants. No threat from these little paper windmills made for sandcastles, as we dream of beach weather!