Thank you XKCD - This might be a regional thing. Where I grew up (in Canada) "a couple" was a vague term meaning "roughly two," but when I moved to the South Eastern US this was a source of confusion frequently - here "a couple" seems to mean "exactly two" not "roughly two." This cartoon is consistent with my understanding, but the author is from Massachusetts. Its possible that the English spoken there is more similar to that spoke in Ontario than that spoken in Georgia.