IOU is a trick to mislead people, after several times of IOU, people don't know the original ownership, what should belongs to them now belongs to banks 
Unfortunately, the trick is not the IOU itself. It is not even its mistaking for money. The trick is using this confusion between debt and money to control other people.
, they also intuitively understand it and conduct their lives accordingly. Never questioning and assuming just the opposite that IOU's are in fact representative of a commodity and and/or time value, forgetting the IOU's loosely regresses back, are in fact a promissory note for an IOU of a common commodity utilised as a medium of exchange.