Then the tide comes in and really confuses you. 😀
That analogy fails/succeeds because it illustrates exactly what yunki is talking about. The grain of sand can see billions of other grains of sands, but it can’t see far enough to see the grass, road, sky, sea, etc.
Most of us will have have heard that there are roughly a similar number of stars in the universe as there are grains of sand on all the beaches in the world.
Here’s some working to add some figures to that:
http://astronomy.swin.edu.au/~gmackie/billions.html