The water on Earth moves about the Earth in what is known as the water cycle.
Because it is a cycle, there truly is no beginning and no end.
The very same water molecule found in your glass of water today has probably been on the Earth for billions of years
It may have been in a glacier or far below the ground.
It may have been high up in the atmosphere and deep in the belly of a dinosaur.
Who knows where it will end up today, when you’re done with it!