This is just way too out there to put in any other thread - yes, I have been a grammar geek since childhood. (Good grades, no friends.) Anyway, I was always under the impression that the saying was "all of a sudden", but lately I hear and read people saying "all the sudden" or "all of the sudden". Certainly I shouldn't be losing sleep over it - but every time I hear it - my brain just gets a little bit more fried. And I don't have enough of it left to fry - especially over "a sudden" or "the sudden".