I remember watching an interview of William Shatner on the old Bob Costas interview show "Later". It was over 20 years ago, on NBC at like 2:30 am, and was a surprisingly good show. Costas always did good interviews, and got his guests to answer questions I never heard them talk about anywhere else. I guess they figured shit, this is gonna be on so late no one will watch it anyhow, so I may as well say anything. Plus, Costas was always very knowledgeable about the guests, and didn't ask the typical questions.
Thanks to the wonders of YouTube, I found the show. The part that stuck with me for 22 years was when Shatner talked about his theory on why Star Trek was so popular. He talked of Joseph Campbell, and the common mythology all cultures shared, and remarked that we have no real mythology in modern times. He thinks Star Trek may fulfill the need modern people have for a cultural mythology.
In the sense that mythology passes along values and lessons for a culture, I think he may be onto something.
All 3 parts of the episode are linked to below, and the portion on mythology is about halfway through the second part: