How did the Nile River shape life in ancient Egypt?

Picture a long ribbon of green threading through an ocean of sand. That ribbon is the Nile, and without it, ancient Egypt simply would not exist. Almost everything the Egyptians grew, built, traded, and believed traced back to this one river — the longest in the world. So let's follow the water and see how a single river built a whole civilization.
Here's the strange part: rain almost never fell on ancient Egypt. The desert was bone-dry. So how did anyone grow food? Once every year, far to the south, summer rains swelled the river until it overflowed its banks. The Nile flooded — and that flood was the best thing that could happen.
