the classical beginnings of civilization were at particular settlements in Sumeria and Egypt. they had no contact or influence with each other.

we would call those the "classical" beginnings of civilization because they lead to classical civilizations which we all study. there are a few points to be made.

they did not appear fully formed as you suggest. the Sumerians began like any other, living in huts and eating fish from the ocean. however they advanced along classical lines, unlike other cultures, making use of mathematics, business accounting, developing astronomy, and later inventing the written word.

there are numerous examples of nonclassical civilizations that, like the Sumerians, grew from hunter-gatherers into civilizations in their own right, but unlike the Sumerians either remained Neolithic for the longest time, like the Japanese, American Indians, Dravidian Indians, Meso-Americans, and South American Indians, or countless unknown others which disappeared entirely like the settlement at Cuatal Huyuk, one of the few that left a trace.

the Egyptians did appear slightly advanced. they were not indigenous to the area but were invaders, part of the "Sea Peoples" who displaced settlements along North Africa, the Levant and the Mediterranean at the murky depths of the dawn of history 7500 years ago. nobody knows who they were or where they came from. we can say they were "slightly advanced" because they could build better huts than the indigenous Egyptians they overtook.

the past of humanity is almost completely unknown but it's no secret. it consists of hunter-gatherers all around the world who settled down to raise crops and live in huts.

p.s. you are all damned stupid and ignorant.