Here's why:

* Galaxies: Estimates suggest there are hundreds of billions, if not trillions, of galaxies in the observable universe. This is a mind-boggling number.

* Grains of Sand: While a beach has a lot of sand, even the largest beach on Earth wouldn't contain even a tiny fraction of the number of galaxies we estimate exist.

Think of it this way: The observable universe is incredibly vast. We can only see a small portion of it, and even in that portion, the number of galaxies is astounding. The number of grains of sand on a beach, while large, pales in comparison.