In addition to the influence of the Roman Empire, and the Greek colonialism which preceded it, the Greeks and Romans also seem to have been the most meticulous collectors, specifically in writing, of their own mythology as well as that of other peoples. They were also quite liberal syncretists: they freely combined their gods with those of foreign peoples whom they encountered, or at least they found it easy to identify their gods with those of others. This is why it's so easy to overlap Greco-Roman myth with other mythologies, or to interpret the latter in terms of the former. As far back as Herodotus (400s BC) the Greeks were writing down the names by which they thought Arabs called Dionysus and Ares, or what the Sudanese thought Zeus and Poseidon looked like.Most people I know are more familiar with Greek/Roman mythology than any other type. I assume this is due to the far-reaching influence of the Roman empire. Do you think there are any other factors?
Although I am Greek, I quite agree with that. Nothing fascinates me more than the story of the Ragnarok.This stuff is taught because of the remarkable influence it had on European history as well as the beauty of the stories.
But sometimes I feel there is a snobbery about the Ancient Greek and Roman world, and that whatever they produced was the best.