TO HELP hammer home to us ignorant primary schoolers one of history's big milestones, our teacher co-opted the old ditty: "In fourteen ninety-two, Columbus sailed the ocean blue."
However, he did advise care with the handy mnemonic.
He referenced a previous pupil, little Jimmy, who — when asked at a later date if he still remembered it — confidently recited: "In fourteen ninety-three, Columbus sailed the deep blue sea."
We're naturally talking about "discovering" America. Except it was mostly hokum. The indigenous Americans notwithstanding, it took Columbus three expeditions before he actually made it to the mainland in South America, still thinking he was tootling around in east Asia.
I recall the odd reference to Erik the Red and Leif Erikson jaunting across icy northern oceans, but they seemed to be regarded as mad Vikings who didn't really count. Still, archaeological evidence uncovered in the 1960s incontrovertibly proved Norsemen had been in (North) America about five centuries earlier than Columbus.
More controversially, recent advances in DNA analysis also suggest the continent's first peoples didn't arrive via a Siberian/Alaskan land-bridge, as per conventional wisdom, but spread east from initial western seaboard landfalls.
The jury is out, but even if irrefutable evidence on behalf of the latter theory emerged tomorrow, one could still confidently predict a huge pie-fight from the orthodoxists. It's par for the course.
Take the first proponents of the continental drift theory involving tectonic plates migrating around the Earth's crust.
When serious advocates of the theory, such as Alfred Wegener, weren't just being ignored by the orthodox, they were either strenuously opposed or positively reviled. After accumulated evidence finally proved overwhelming, the hitherto "experts" swapped horses pronto.
Another interesting recent debate that challenges major paradigms revolves around — what else? — the Great Sphinx of Giza. It's perhaps no accident that the clichéd term "riddle of the Sphinx" got to be a cliché in the first place — it seems to have always had an enigmatic aura.
Conventional wisdom says that the "birth" of civilisation occurred about 5000BC to 6000BC, when settled population centres started to aggregate in the "Fertile Crescent" of Mesopotamia.
It's speculated the first proto-urban centres with populations of a few thousand emerged in about 3000BC, then — hey presto — there were suddenly stupendously complex, staggeringly monumental edifices like the Great Pyramid of Giza springing up just half a millennium later.
Orthodoxy says the Great Sphinx was sculpted contemporaneous to the pyramids, but recently several eminent geologists — perhaps most notably Robert Schoch of Boston University — have thrown cold water on the theory. Or, more precisely, rain water. Lots of it.
They noticed that deep-etched erosion on the limestone monolith was a textbook example of substantive water-on-lime erosion. And the last time there was sufficient quantity of water to cause such erosion was when the whole area enjoyed a lush, high-rainfall climate way back between about 5000 and anything up to 10,000 years ago.
Of course, if true, then conventional theories about the "birth of civilisation" go belly-up. No wonder orthodox Egyptologists get their panties in a big twist at the mere thought.
But it's impressive how new evidence for our ancient history is still surfacing.
Only a few decades ago, an astounding complex in southern Turkey was unearthed — Göbekli Tepe, huge, precision-shaped stone megaliths weighing up to 20 tonnes featuring finely-sculpted symbolic motifs.
Their age? Well, roughly about 12,000 years — 7000 years older than the Giza pyramids or the crude slabs of Stonehenge, and all constructed when we were meant to be nomadic hunter-gatherers in animal skins.
Of course, time may prove such speculation bunkum.
But then again, it may equally prove current orthodox theories on human history timelines are as shonky as Columbus "discovering" America after sailing the ocean blue in fourteen ninety-two. Or was it the deep blue sea in fourteen ninety three ..?