KISS Principle

If

"Keep it simple, stupid" came out of aircraft design, where the requirement was that a jet be repairable by an average mechanic in a field with basic tools. The test was never elegance — it was whether an ordinary person could fix it in the worst circumstances the thing would actually meet.

Then

Judge a design by who can repair it at 3 AM, not by how it reads in review. If the on-call engineer needs the author on the call, it is not simple — it is familiar to one person.

Unless

Ashby's Law of Requisite Variety — a system simpler than the problem it has to regulate cannot cope with it, and simplicity below that floor is displaced complexity rather than less of it