I'm very curious where that saying comes from now. I haven't found anything conclusive, like [1]'s friend I thought it might have been Douglas Adams, but a few references refers to it as "Grave's Law". After a few searches, I can't find any references to that which I can date further back than '99. But variants of the saying is at least as old as '89 (Rick Cook's version in [1]), but it's the kind of thing that sounds like a sufficiently "obvious" extension of the far older view that human stupidity has no bounds that it feels surprising if it is that recent.
[1] https://www.samyoung.co.nz/2025/03/building-better-idiot.htm...