The ancient Greeks knew the simple truths of world history … our real history before it was Christianised.
Plato wrote of a world calamity in which mankind was destroyed by fire and flood leaving only a few ignorant and illiterate survivors with no written word.  Up until about 100 BC the Athenians still celebrated performances in commemoration of the devastations of the deluge, and Plutarch plainly emphasised … …there must have been some actual calamity… [with] something real as its true cause. 
Around 700 BC the Greek philosopher/historian Hesiod recorded that we are descended from heroes who perished in the dreadful battle for lovely-haired Helen (of Troy). The noble heroes of the 4th race ‘most fair’ were largely wiped out … but some survived and settled at the far ends of the Earth in the Islands of the Blessed. We are now the 5th race … destined to waste away in toil and pain … showing no affection, but rudeness and cruelty … lawbreakers [who] sack one another’s cities … evil-doers and scoundrels …base men, blighted by envy, taking joy in the ruin of others … lingering in grief and pain.  We are just miserable remnants characterised as … degenerate, cruel, unjust, malicious, libidinous, unfilial and treacherous. 
Elsewhere, the Athenian statesman Solon (Plato’s grandfather) recorded a visit to Egypt where priest/scholars informed him in very plain language … you Greeks are mere children, pathetic, illiterate survivors of uneducated mountain shepherds who happened to survive the flood. 
But these were not popular sentiments in the modern era, especially not in the Christian era. The Classical authors were disparaged … Plato especially was lampooned and his Timaeus derided as an early example of science fiction. The old knowledge was disparaged, ignored and eventually forgotten … we preferred the romance of the new religion.
Now new research suggests the ancient authors were right all the time. We are confronted with three unresolved puzzles in orthodox accounts of world history. Three elephants in the room!
One – in the previous era of the so-called ‘Ice Age’- planet Earth revolved happily for about two million years in a regular, upright orbit of exactly 360 days per year. But then about 10,000 BC everything radically changed. Suddenly, within about fifty years, ocean temperatures increased by around 10 degrees, continental ice caps melted, the sea level rose dramatically, the polar axis was displaced by about 23 degrees, and the solar orbit was skewed to an irregular ellipse of 365.25 days. How and where did that happen so suddenly?
Some observations are recounted in the Iliad of Homer where a worldwide calamity struck the isle of man … ‘what tract on Earth is not full of our agony’. Ilium was overwhelmed by fire and flood … and darkness was upon the deep.
Two – in the Iliad account, prior to the final catastrophe Cassandra issued a warning that ‘the sky was falling’ … at which Prince Aeneas paused to collect the sacred fire of the hearth and, with his kin, he sailed away to safety. Aeneas and his kin were ‘survivors of a noble race’ … but where did they go to, and what was the ‘sacred fire of the hearth’?
Three – modern anatomical man, physically more or less like us, emerged out of Africa a few hundred thousand years ago. But modern ‘civilised’ man with written language, tools, skills and social organisation only emerged very suddenly about 5000 BC, in Mesopotamia. In a regional background with a typically sparse population of wandering primitive hunter-gatherers there suddenly emerged, by boat, a settlement of sophisticated people with writing, pottery, tools, jewellery, brick construction, agricultural skills, laws and social organisation. They called themselves Sumerians … ‘civilised lords’.
Who were they and where did they come from?
Even the questions are now lost to orthodox history but fortunately, some answers are preserved in remnants of ancient texts and in the rich veins of folklore, legend and mythology.