...here's one theory floating around.

Waaaaay back in one of the -olithic eras, if a caveman needed something he got it by the only means he knew how . He got a bison leg and pasted another caveman over the head and took his stuff. This worked well for many years until some of the weaker cavemen got tired of getting their asses kicked in. They decided that bartering was a much better system wherein they would trade something for something else.

The first problem was to figure out what to barter with. Not everyone always had something that the other guy wanted in return and often one guy would still get pounded. Someone made the suggestion that maybe they could use something that they could all acquire easily .... rawks as they spelled it back then. This worked ok for a few days until they realize that the place was lousy with rawks. This made every caveman a bajillionaire overnight. Also, when the guy traded his stuff away for rawks he ended up with a huge assload of rawks that he couldnt unload. This was not a such a good idea so they chunked the guy who came up with that idea into a tar pit. The national past time for the cavemen.

back to the drawing rawk.

A guy named boog thought that maybe BIGGER rawks would be a better idea because they would be harder to acquire, but that proved worthless because they wouldnt fit into the billfolds that farg had just invented and patented yesterday. They couldnt seem to get away from the original rawk idea. They just knew that there was something to the rawks but they couldnt get past the fact that they were as dumb as a sack full of them.

Then one day while the cavemen were having a tailgate party at the 49th game of the world cup throwing a guy into the tar pit playoffs a cavemen named ralph had a brainstorm.

"Why we dont invent checkbooks?"

Brilliant! then they could leave thier BIG rawks at home and promise to pay later when they had time to haul them to the other person. This worked for a week until people started lying about having any rawks at home. Soon people were floating hot checks all over the place.

A mob got together and pounded Ralph senseless with his 17 foot granite check book and took all his stuff.

No one wanted to come up with any more ideas after that because they always ended up eating tar or being fed to a saber-toothed fruitbat. They all agreed that if they ever saw another person wanting to trade something it would be 30 million years too soon as far as they were concerned.

30 million years later little shiney yellow rawks were discovered and the gold standard was invented