The hobbit: The desolation of smug

Modern capitalism as we know it began forming in the Renaissance, particularly in colonial European powers who were getting to the Colonization of the rest of the world game earlier than their peers. This notably includes Portugal and the Netherlands, followed swiftly by most everyone else.

There were promissory notes that were carried by travelers prior to this, in the form of Crusaders traveling from Europe to Jerusalem, in the relatively brief period of time that it was conquered. But this did not interact with market economies as we'd know it, and is directly analogous to traveler cheques, meant to make you less of an appealing robbery target on the road.

No, these kinds of shenanigans were concocted rather recently, and are not reflective of baseline normal human behavior. It's mostly a system that was created by accident, with conventions that were forming being purposeful altered during creation by the people with money, for their own benefit.

Look closer, it's squares. They're all proof of stock.