kaikki muumit laaksossa

Finnish

literally: "all the Moomins in the valley"; from the Moomin stories, in which the protagonists live in the Moomin Valley

(idiomatic) mental ability or sanity; chiefly used negatively to indicate that someone is mentally deficient or insane
Olen alkanut epäillä, että hänellä ei ole kaikki muumit laaksossa.
I have begun to suspect that his elevator doesn't go all the way to the top.