The fact that people give money to the US, or any country, for essentially an IOU slip of paper promising to pay you back with interest is so weird.
Speaking of gold reminds me of this sci-fi book where aliens come to earth and cause damage. They ask how they can make things right and are explained gold and the monetary system. They go oh, we can totally filter gold from the oceans and pay you back in tons of gold per day. This caused panic as the huge influx would crash the system. I think it was an asimov short story.