We tend to think of road rage as being a recent phenomena. It's certainly more common nowadays, but I believe it has been around for centuries.
There surely would have been chariot rage on the Roman roads. There were simply too many chariots not to have had an incident where one chariot cut off another, or one was going far too slow. After all, it's well-documented that "the finger" has been around for centuries. Where else would it have been invented?
But the concept seems funniest to me on the high seas.
"Hey, Columbus! Get your damn caravel out of the harbor! Could you sail that thing any slower? Admiral of the Ocean Sea, my ass!"
Of course, Columbus no doubt followed the heckler for a few miles before blasting a cannon at him. Sea rage at its finest.
My brain is a curious thing. It bounces from place to place, from the exceedingly strange to the terribly mundane. Every once in awhile, something will pop into my head that is just completely out of nowhere. Totally random.