Though one thing I've known for a long time, perhaps not as embedded but still fun, is that Stephen Sondheim invented the phrase "everything's coming up roses." It was not a thing people said; it was a thing he devised.
I can't just this second think of another weird one-off phrase that has so embedded itself in the English language like "jump the shark" has.
I'd think that most people would have no idea whence it came had they not been specifically told.
To be sure it's a play on the name of Gypsy's main character (though of all the Roses I've ever seen, only Imelda Staunton acknowledged it, for a half second, the first time she sang it), but it did inspire director Jerome Robbins to inquire "Everything's coming up Rose's what?"
I mean, it wasn't like she had a lot of time on her hands at the moment, but Staunton made this tiny "oh look I made a joke" face, and it was marvelous. And I think that that was the last fresh insight anyone is ever going to squeeze out of that role.
By the way, both this and his other lyrics and commentary collection, Look, I Made a Hat, are fascinating and funny. Read the verses he wrote for "Officer Krupke" that weren't used! Learn why he wrote either at the piano, or reclining on a couch!
No, that one seems to have been knocking around for a few years and had appeared prominently in print at least once before Company opened. So it was, it seems, in the air waiting to be written down.
