Actress Diana Lynn appeared in the original film, "The Major and the Minor," as Lucy, the science-obsessed teenage sister of Pamela (Ginger Roger's on-screen nemesis). Thirteen years later, Diana Lynn starred in that film's remake, "You're Never Too Young," this time as Nancy Collins (a female version of the role originally played by Ray Milland).
Emory Parnell plays the same part (train conductor) in the original version, "The Major and the Minor."
Mitzi McCall's debut.
Since this is widely acknowledged to be a remake of the 1942 Ray Milland and Ginger Rogers vehicle "The Major and the Minor," it is unclear why 3 of that film's writers - Charles Brackett, Billy Wilder and playwright Edward Childs Carpenter - are not credited here.
At the 1:30:00 mark into the movie, Gretchen's brother, Mike, who Wilbur has been staying with, discovers that a rock that Wilbur gave him is in fact the Juba Diamond that was stolen and involved a murder. As he breaks the window with the glass, a tune is whistled from off stage, and Jerry Lewis (Wilbur) enters into the room whistling the tune.
The tune is actually the opening tune heard on the radio program, and than later on, TV program, called "The Whistler", which aired on radio from 1942 to 1955. then on TV for a short while, and also existed as a series of films.