VOQOTD: rudiments just made up by a couple of guys

Well, not exactly: many or most of them have been in use for a couple of hundred years at least, but the 26 Standard Drum Rudiments as a thing... read this letter to Percussive Notes by William F. Ludwig, Sr. (1879-1973), written a few months before his death, 41 years ago— he's writing in response to an opinion on updating the rudiments, but that's not important:

When I [!!!] established the 26 Rudiments as a standard system of drumming for the American school drummers in 1923, with Sanford A. Moeller [!!!], I did not imagine that they would last forever. But the system has held up very well all these 48 [!!!] years,  and it has proven itself by building the world's best drummers. I believe this is quite a record and naturally would like to see it continued. In the early 1920's no one was around who was even interested in establishing a uniform system of drumming and I felt it my duty, knowing what rudiments had done for me. It took many years to establish the 26 Standard American Rudiments and it was expensive [!!!] but the leading percussionists of that day stood by me.

The exclamation points are mine. As with a lot of things that seem carved in stone by God, with the beard, robes, and everything, it was really just a couple of guys deciding on an idea, and then marketing it to the point that everyone accepted it. I'm also always amazed at how compressed the history of American drumming is; in the 48 year span he mentions, we go from Baby Dodds to Jack Dejohnette— about the first decade of either of their careers.