Once upon a time the Phrygians didn’t have a king. Very careless, forgetting where you put your king. So they did the only reasonable thing and consulted the Oracle at Telmissus. The oracle decreed that the next man to enter the city driving an ox-cart should be crowned king.
What have we said about ignoring oracles? Right. So when Gordias the Peasant came into the city driving his ox-cart, the people immediately made him Gordias the King.
Since kings rarely have need of an ox-cart, Gordias dedicated his cart to Zeus and tied it to a pole with the World’s Most Complicated Knot.
The oracle then predicted that whoever Undid the Knot would rule all of Asia. Since oracles are always (emphasis on ALWAYS) right, many a person came to try to untie it. This was great for tourism and nail salons (it was not possible to untie the Knot and many people broke important fingernails trying).
On and on this went and everyone was reasonably happy with the status quo except all the people who didn’t untie the knot. Although since no one else could untie it, and there were plenty of manicurists, no one got too futzed.
Eventually (historians disagree about how many years are in an “eventually”), young Alexander the Great came to Phrygia. A the G was The Dude of the time and planned to conquer pretty much everywhere (Asia Minor is most definitely part of “everywhere”). Alex took a look at the Knot, realized the ends were missing, re-read the plaque (all tourist sites have plaques), and then took out his sword and sliced the knot in half.
Alexander the Great went on to conquer Asia Minor. Because, oracle. Also, he was a really incredible battle strategist.
To this day, Gordian Knot refers to a complex problem, and cutting the Gordian Knot means finding a ridiculously simple solution to a crazy looking problem.