Said to acknowledge someone else's explanation of something and thank them for it, with the added undertone of acknowledging that yeah now that you think about it, really that should have been obvious all along and you were being stupid for
even asking the question in the first place.
An early (and possibly the first) appearance of the phrase, with this undertone, occurs in a
joke in the 1992 episode "Holoship" of
British sci-fi comedy TV series Red Dwarf, with the following exchange:
The Cat : Why
don't we drop the defensive shields?
Kryten : A superlative suggestion, sir. With just two
minor flaws. One, we
don't have any defensive shields. And two, we
don't have any defensive shields. Now I realise that technically speaking that's only one flaw but I thought that it was such a big one that it was worth mentioning twice.
The Cat : Good point, well made.
