Famine, cannibalism, disease, crime – it was widely rumored in ancient Egypt that during a terrible time in its past the forces of isfet (chaos) completely upended the orderly society of which Egyptians were inordinately fond. The first “intermediate period” between kings became the subject of several Middle Kingdom teaching or wisdom texts, such as The Prophecy of Neferti and The Admonitions of Ipuwer. These writings essentially bemoan the terrible things that are supposed to have happened, and warn readers to maintain maat (balance, justice) in order to avoid a recurrence.
Here’s the thing – there is no real evidence that the catastrophic events actually happened. Modern scholars lean towards the idea that they were written primarily as propaganda, reinforcing the importance of unifying under the king, keeping religious observances of the neteru (gods), and keeping things on an even keel.