The thousands of walnuts used for the scene of Laura descending from the closet were supplied to the show by walnut wholesalers. Rob Petrie actor, Dick Van Dyke recalled that the actors and crew were allowed to eat as many walnuts as they wanted - eventually causing many of them intestinal problems from over-consumption of the low-fiber nut meat. After the show, the producers returned any unbroken walnuts to the wholesalers - most of which ended up on store shelves.
Producer Sheldon Leonard hated the story when it was presented as a script, thinking it was not funny and too strange, but gave the go-ahead for it to be filmed. Later, he acknowledged the popularity of the episode and said he had been wrong to think it would flop.
This is the only episode in which Buddy Sorrell never insults Mel Cooley.
As he leaves Rob's office, Kolak (Danny Thomas) hums "Danny Boy," the theme to "The Danny Thomas Show."
Dick Van Dyke mentioned his top five favorite episodes in a three-hour special televised on Nick-At-Nite (Nickelodeon, in evening & night time hours, 6:00 P. M. until 5:00 A. M., the next morning). This special broadcast was approximately a month before TVLand began. He said Where Did I Come From? (1962) is his all-time favorite episode. The rest of his top five favorites, in descending order, were: The Attempted Marriage (1962), It May Look Like a Walnut (1963), I'd Rather Be Bald Than Have No Head at All (1964) & Never Bathe on Saturday (1965).