The conservation of Complexity (Tesler) seems immediately insightful to me just as a sentence:

  "Every application has an inherent amount of irreducible complexity that can only be shifted, not eliminated."

But then in the explanation seems to me to devolve down to a trite suggestion not to burden your users. This doesn't interest me because users need the level of complexity they need and no more whatever you're doing and making it less causes your application to be an unflexible toy. So this is all, to a degree, obvious.

I think it's more useful to remember when you're refactoring that if you try to make one bit of a system simpler then you often just make another part more complex. Why write something twice to end up with it being just as bad the other way round?