It's also called the law of "Uphill Analysis, Downhill Invention" which states "It is much more difficult to guess the internal structure of an entity just by observing its behavior than it is to actually create the structure that leads to that behavior."
(There is a blog-post version behind this link as well, in case anybody wanted to skim the contents rather than watch video of the entire talk to find out how it fits in.)
Been reusing and repeating this one quite a lot, since I saw it mentioned in one of this year's RubyConf keynotes: https://blog.jessitron.com/2019/11/05/keynote-collective-pro...
(There is a blog-post version behind this link as well, in case anybody wanted to skim the contents rather than watch video of the entire talk to find out how it fits in.)