know which end is up
- (idiomatic) To possess sound judgment or common sense; to have a clear understanding of a situation.
- He was too stoned to know which end was up.
- 1992, Dorothy Garlock, Glorious Dawn, →ISBN, (Google preview):
- He's so in love, he doesn't know which end is up.
- 2005, John C. Hefley, Failure Equals Death, →ISBN, p. 29 (Google preview):
- “I'll gladly take criticism from a cop who knows which end is up and isn't afraid to do the job the way it should be done.”
- 2010, Gordon Lish, "The Friend" in Collected Fictions, →ISBN, p. 243 (Google preview):
- “[B]elieve me, she is some catch for the right boy—for a boy which knows which end is up.”
- 2011, Catherine McGuinness, Emperors' Clothes, →ISBN, 9781937110048, (Google preview):
- The whole company is in disarray! Nobody knows which end is up.
- Usually used in negative constructions, such as:
- 2011, Richard North Patterson, Silent Witness, →ISBN, p. 277 (Google preview):
- “When someone doesn't know which end is up, who knows why they do things.”