But you're thinking is slightly warped in that the GDP can count the same money multiple times -- the little parable about the town where everyone is indebted to everyone else and the money from the visitor's wallet [$100, as I heard it] is 'borrowed' to pay back the one, who pays back the other until everyone's debt is cleared and the money then returned to the visitor is a good example: even though the total amount of the services the debt pays off is something like $600 there was only ever the $100 note in the story.
LOL! Well, I was talking about the real world.
Of course the entire money supply is not currency. However, isn't the reason some dollars can be used more than once is because of the fractional reserve banking system that would be abolished with a strict gold standard?