Wiktionary
adv. 1 (context idiomatic English) Having fantastic or impractical dreams; thinking impractically. 2 (context idiomatic English) daydream; thinking about matters other than the present reality.
Wikipedia
Head in the Clouds is a 2004 Canadian- British war drama film written and directed by John Duigan. The original screenplay focuses on the choices young lovers must make as they find themselves surrounded by increasing political unrest in late-1930s Europe.
Usage examples of "head in the clouds".
He girds his loins, squares his shoulders, and with a smile on his lips, a glint in his eye, his feet on the ground, his head in the clouds, his back to the wall, a song in his heart and a spring in his step, puts his nose to the grindstone and lets George do it.
He was grateful that no one had seen the raging head in the clouds.
He was grateful that no-one had seen the raging head in the clouds.
In my opinion, you have your head in the clouds, and I want to bring you down to earth.