to be on another planet | what planet is somebody on?
idiomPart ofplanet
to be on another planet | what planet is somebody on? — idiom
1. said, often humorously, when someone seems so far from real life that their idea
1.idiom
Definition
said, often humorously, when someone seems so far from real life that their ideas sound wildly impractical.
Example
Dad says a weekend trip with four toddlers is relaxing; what planet is he on?
When the manager cut half the budget, Lina said he was on another planet.