Even the things that developed from something else had that moment when they became identifiably (whatever).
Computers, wheels, preserved food, TV dinners. There is a point at which a used book becomes salable as a Used Book.
Origins are one of the chief foods of mythology. All those constellations. Arachne.
Didn’t Paul Bunyan accidentally make the Mississippi?
Of course, not all beginnings are known, and many that are known are not favored with a fable.
(Getting the drift?) Think of something. Everyday as a light bulb, or the light bulb cartoon icon; or outré as only you can imagine and give yourself a little time with it.
How the heck DID it come into being?
Can you compress that into the three lines of a haiku?
Take all the words you want, but make a minor myth.