First of all I go to a Greek school so I know that half the words in the English language are Greek pre fixes AND you won't believe this one but it's true : nobody knew that the earth was round until Christopher Columbus discovered it well he didn't Greeks discovered this because of the lunar eclipse because the shadow was round and in order for a shadow to be round it would have to be a sphere
The Greek mythological stories of Zeus, Poseidon, Hades and all the other gods are all from their imagination. The Romans just copied their gods and their stories from the Greeks. The only difference that I see is that they just changed the names of the gods. And besides, the Romans aren't known for their Mythological stories.
Greek mythology is the original, and its always nice (and more interesting, from an intellectual point of view) to go back to the [more] original source and learn from them. The Greeks had amazing myths that shifted over the course of their civilization, which the Romans later inherited and altered for their culture.
While it was fascinating in elementary school to get the basics of how Romans and Greeks justified how the world worked, at the same time it all sounded a bit ridiculous to me. Neither one of those mythological foundations held much interest in me. I'm more of a modern guy, I like my mythology set in space, such as Star Trek and Battlestar Galactica.