A couple of days ago I was in the supermarket with my father. Amongst the items on his list was butter and it turned out that the brand he wanted was on special. Buy 2 for £5.00 the poster shouted. Only thing is Dad didn't want two. So he picked them up anyway, and said he'd give the other one to me. About five minutes later it suddenly dawned on him that his one packet of butter had just cost him £1.40 more than if he'd just bought the single one. Hmm, maybe not a bargain after all?
And that, Dear Reader, is why you might have seen a middle-aged lady and her father stopped dead in the middle of the bread aisle of a well-known supermarket the other day, laughing their heads off like a pair of fools.