On another planet
Meaning
To be completely out of touch with reality, oblivious to what is happening, or utterly eccentric.
Origin
The notion of "another planet" has captivated human imagination for centuries, but it wasn't until the surge of space exploration and science fiction in the 20th century that it solidified into a common metaphor for extreme detachment. As rockets blasted off and futuristic tales filled screens and pages, the idea of a distant, alien world became the ultimate symbol for someone utterly disconnected from earthly reality. This vivid image of being physically remote in space then seamlessly translated into a description of someone mentally adrift, oblivious, or eccentric, giving us a punchy way to describe those whose minds seem light-years away.
Examples
- When I tried to explain the new office policy to him, he just stared blankly, like he was on another planet.
- Her ideas for the project were so bizarre and impractical, it was clear she was on another planet.