But 'ancient Egypt' is a term that serves to cover three millennia of time. Here's a startling reminder of the extreme longevity of this civilization, if that's what you can call it: you are closer in time to Cleopatra (died 30 BCE) than Cleopatra was to the builders of the Pyramid of Khufu (completed 2560 BCE). Tutankhamun was about midway between the two, living as he did in the fourteenth century BCE. You are closer in time to the Visigothic kings of Spain than Tutankhamun was to Khufu. (John Green makes a similar point in his fun, and actually rather good, 'Crash Course: World History' episode on Ancient Egypt.)
Egypt is impossibly ancient, the kind of age that puts other human societies into stunning perspective. It wasn't a period, or a sort of civilized prelude to Greeks and Romans, but possibly the longest-lived literate civilization on earth, ever. The competition comes from Mesopotamia, but there are fewer examples of such extreme sameness over such long durations. Egypt wasn't politically unified for the entire time - see, for instance, this map of political divisions in the Third Intermediate Period - but the reason ancient Egypt seems like one place, in which Cleopatra shared a two-dimensional walking dance with Khufu, is because some things stayed nearly the same over three thousand years.
|The Narmer Palette. This is from 5100 years ago. 5100. h/t Wiki.|
Of course, there were changes in ancient Egypt. Khufu's pyramid was built with huge blocks of stone transported over rivers and up ramps by teams of workers, and it is true that this style continued in use for some time. Monumental architecture is characteristic of public sites in early Egypt. But by the time of Akhenaten, around 1350 BCE, workers used much smaller blocks, ones that could be carried by a single man. These are conventionally referred to as talatat, after the Egyptian Arabic word for 'three', referring to the three-handspan length of each block (about a cubit, or 45 centimetres). Akhenaten also imposed changes in iconography related to his belief in the Aten, but these were not long-lived. Akhenaten's Egypt would doubtless have seemed strange and foreign to Khufu, had he seen it.
|The Small Aten Temple at Akhetaten, aka Amarna. Built using talatat. h/t Wiki, User: Markh.|
Due to their flexibility, hieroglyphs were used to write several variants of the Egyptian language, including Archaic (in the earliest inscriptions), Old (roughly the time of the Old Kingdom), and Middle (the 'classical' language of Egypt until the Roman conquest, in which most of the great Egyptian literary works were composed). The language changed, as spoken languages always do, but the hieroglyphs remained basically the same. In addition to hieroglyphs were the hieratic script, which dates from approximately the same time as hieroglyphs and uses stylised versions of hieroglyphic characters; and the Demotic script, used to write a later form of Egyptian from c.650 BCE. At which point, I hasten to add, Egypt had been using hieroglyphs, largely unchanged, for about two-and-a-half thousand years - nearly the time from the beginning of Demotic up to now. The Greek and Roman alphabets are only just beginning to approach that age.
|Hieratic script. Image in the public domain, but see Wiki.|
Egypt is perhaps the only literate place on the planet where there is such obvious cultural continuity, where even the written record attests to the incomparable age of the lifestyles found there. But it's relatively easy to find continuities of a sort in prehistory. At Cuddie Springs, an archaeological site in New South Wales, Australia, archaeologists have discovered remains of Pleistocene megafauna in human-associated contexts for a period of over seven thousand years beginning about forty thousand years ago. These now-extinct megafauna included Genyornis and Diprotodon, a gigantic flightless bird and a three-metre-long giant wombat respectively. For seven thousand years, humans lived alongside these creatures in that part of Australia. They woke up every day for seven thousand years with the prospect of seeing, and perhaps killing, an enormous wombat.
|Genyornis - a companion and prey of Australian communities for a period longer than the presence of farming in western Europe. h/t Wiki, User: Nobu Tamura|
All of which is just to remind you that the universe is vast, ancient, and inscrutable, and that everything you take for granted and think of as normal and essential to life is dust in the wind.