Who knew?

Who knew?

Used rhetorically to express surprise about some revelation. Sometimes used ironically or sarcastically. Wow, it turns out that skinny little Mike Thompson has an incredible baritone singing voice. Who knew? A: "Man, this class is tough." B: "Yeah, who knew computer engineering would be so complicated?" A: "Har har, very funny."
See also: who
Farlex Dictionary of Idioms.
See also:
  • (Is) that everything?
  • believe it or not
  • bion
  • as one does
  • come in
  • come in a certain position
  • come on in
  • as you do
  • a little goes a long way
  • first rule of (something): do not talk about (something)