you had me at (something)

you had me at (something)

You convinced me of something or won me over when you said something in particular (mentioned after "at"). A: "Want to come over and go swimming? Also, my parents aren't around, and they left me money for food." B: "Hey, it's 95 degrees—you had me at 'swimming.' Be right over!" You had me at "free." Where do I sign up?
Farlex Dictionary of Idioms.
See also:
  • a/the feel of (something)
  • (I) wouldn't (do something) if I were you
  • a straw will show which way the wind blows
  • a crack at (someone or something)
  • all right
  • (you) wanna make something of it?
  • all for the best
  • a thing of the past
  • a slew of (something)
  • a bird in the hand