be (living) on another planet

slang To be oblivious to one's surroundings or act strangely. I have no idea what the professor said during today's lecture because I was on another planet the whole time. The millionaire investor always says something wacky in the board meetings—it's like he's on living another planet.

Common Names:

Name	Pronounced	Usage
Piritta	PEE-reet-tah	Finnish
Jachin	JAY-kin (English)	Biblical
Dada	-	Western African, Yoruba
Sixtus	-	Late Roman
Shayma	-	Arabic
Rosamund	ROZ-ə-mund	English (Rare)