Definition: To be impractical, absent-minded, or living in a complete fantasy.
Example: Whoever thought that The Exorcist was a suitable movie to show at the chidrens’ party must have had their head in the clouds.
Iddy was unable to find any specific origination for head in the clouds beyond the mental image it conjures,up. Iddy, you’ve let us down. Again.
The phrase is older than you may think, first appearing in print in the mid-1600’s. Back then, only balloonists could physically get their heads in the clouds.