Refers to a
joke which becomes much less funny if it requires an explanation.
Farcically derived from a nonsense
situation whereby Einstein and his assistant at the
time have just finished explaining, in great depth, the workings of hie great Theory of Relativity. Upon finishing the lecture, the gathered scientists and philosophers look a little non-plussed an tentatively applaud Einstein for his great
work . . . though really they
don't quite understand it. Whilst accepting the applause graciously, Einstein turns to his assistant, who happens to be chuckling, and mutters "See, I told you, it's nowhere near as funny when you have to explain it (!)"
First credit for this original word/concept must be given to Ian James
Hay, for it was his peculiar mind that created it :)