What was (one) thinking?

What was (one) thinking?

Used to express confusion, annoyance, or surprise at someone's past opinions, decisions, behavior, etc. You picked bright, neon-red wallpaper for our bedroom? What were you thinking? A: "What were you thinking, driving so recklessly like that? You could have gotten yourself killed!"
See also: what
Farlex Dictionary of Idioms.
See also:
  • What was (one) smoking?
  • OMG
  • geez
  • geeze
  • jeez
  • Jeez!
  • jeeze
  • Louise
  • geez Louise
  • jeez Louise