Watching the Discovery Channel the other day, I saw something about the "Big Bang", where they were talking about other stars, other galaxies, how far apart they are, how small earth is compared to our sun.. and how small OUR sun is compared to some of the other stars. It is truly amazing. Consider all of the stars out there, and how far away they are, each of them. Also, think about how their brightness may detract from or mask the signature of other stars [of course, we're talking about naked-eye observation, which the scientific community isn't using for mapping the universe].
To consider earth as big as a grain of sand if the expanding universe was a beach the size of earth is pretty much over-inflating our importance. We're nothing.
I'll tell you, in 25 years, my knowledge of space has come a long way, and I don't know shit. When I was in 1st grade I remember having to memorize the planets.
Pluto was a planet, and "Planet X", a planet beyond Pluto was a rumor.
So much has changed.