That sounds insane.
However popular that aphorism is, it isn't actually the definition of insanity.
The former might be a form of the latter, but you can certainly be insane in other ways.
> Insanity is the wrong term, because it would imply repeating something that has already failed.
ie suggesting the opposite of your point; that the term "insanity" is more narrowly defined rather than broadly defined.
No it doesn't. You might be thinking of that meme often miss-attributing that alternative definition as an Einstein wisdom; but that quote is about as accurate as the claim of who said it.