Your assumption is both entirely correct and entirely wrong. How much money do you currently have? The answer is probably not what you think, unless you have a stash of pure gold under your bed.
What you have is "credit" in the form of those promissory notes. Therefor, if the government gives you more credit and the system keeps working, you and your friend are both richer and will have "spent" the money, one way or another. The mere fact of giving you the money has increased the overall wealth of the nation in the only way that matters: by making those promises.
I repeat: money is and always has been a confidence trick. Even when converted into real objects, such as a house or a car, the money represented by those objects depends entirely on what someone will exchange for the real object. This is why financial bubbles like the Tulip Frenzy or the South Sea Company happen.