Correctamundo...yep, it was definitely Strawberry Fields. I remember picking up on that the first time I saw the film, and it amazed me..but being a sort of songwriter myself, and I'm sure David will attest to this, some of those ideas, be it a musical a/o lyrical phrase, get cooking sometimes well upstream of their incorporation into a song.   Very interesting.  Lennon was so right on putting that buffoon in his place.  What's astonishing is that Murray the "K" didn't even pick up on it...or know that the term was a form of insult. 

Gene