OK, starting off my fun here with a really obscure one…
I have a large collection of the Johnny Hart “B.C.” comic strips in book form. There is a strip in one that has always baffled me.
One of the cavemen (either B.C. or Peter, forget which) skips a stone into the ocean. Soon, a message arrives on a floating slab (in the manner in which Peter used to exchange messages with the unseen civilization across the sea). The message on the slab reads: “Nice going – you just sank Bart’s dinghy!”
Who the hell is Bart, and what is the significance of his dinghy? I have googled this many times and found no reference.
Either there is some obscure historical or cultural reference that I am not aware of, or perhaps this is some sort on “in-joke” on Hart’s part. (It is said that the “B.C.” characters were modeled after real-life friends.) Or perhaps it is meant to simply be a nonsensical reference made just to drive readers like myself nuts.