Mystery solved.

Ever since I wrote "Who is Green and what does he shoot?" in yesterday's post,  I've had this niggling feeling that I pinched that idea from somewhere else, but I couldn't think where.  Then in the middle of the night (most of my best ideas come in the middle of the night) it came to me.  It was an episode of "Yes Minister" or maybe "Yes Prime Minister" where Jim Hacker wishing to express his displeasure at some paper he had been given to read, had written "Round objects" on it.  It later resurfaced on his desk, and someone had written below "Who is Round and to what does he object?".  Actually this itself was probably a pinch - there's a long-standing story of someone scribbling "round objects" on a Parliamentary paper and Churchill - then PM - writing next to it "Who is Round? And why does he object?"