Anachronisms and plagiarisms

Somewhere in my novel Lord Byron's Novel I had Byron (as author) describe something lost or forgotten as "gone where Saturn keeps the years," a phrase I had Byron put in quotes.  Becasue of a question that cme up a few postings ago I looked up the quotation, which I've known for years and assumed was, oh, SHakespeare, Pope.  No: It's Edward Arlington Robinson, around a hundred years after.

And last night I was watching North by Northwest and came upon the following interchange between Cary Grant and spymaster Leo G. Carroll:

GRANT:  I don't think I caught your name.
CARROLL:  I don't think I pitched it.

The same joke -- with "tossed" instead of "pitched" -- is in my last novel Four Freedoms.  Could I possibly have remembered it from the movie?  It seemed when I thought it up to be something a little of wiseacres might have said, but I believed I'd made it up.