Have I ever shared my prequel theory with you? In light of the cancellation of Enterprise, here's a good enough time to share it as any. It's pretty simple: A good sign that something has entered our "modern mythology" is whether it's spawned a prequel. That is, if we're interested in a story enough to find out the backstory of its characters, it shows that we've become pretty invested in it. (I note that this isn't always true.)
Interestingly, the main examples I can think of are science fiction and the like. There are the Star Wars prequels, of course, and the reason for this post, Star Trek's latest series. The comics have been giving us backstories of superheroes for decades, of course. It may just be a way of making sure that new audiences "get it," but it seems that most superhero movies begin again with the origin of the character (the 70's Superman, the 80's Batman, the recent Spiderman and other Marvel movies, the upcoming Batman and Superman films, etc.). Of course, now there's Smallville as well.
Although The Hobbit was written well before The Lord of the Rings, it's usually described as a "prelude" to the later stories, and I imagine most of its appeal (good as it is on its own) lies in that fact. Of course, after Tolkien's death, quite a few more posthumous books of "backstory" to the Middle-Earth stories came out.
Outside of sci-fi (but not always!), our modern myth par excellance, Sherlock Holmes, has gotten the prequel treatment as well. Even some of the original stories may be described as such.
Anyway, it's not too profound, I know, but an interesting note. Shabbat Shalom and a good weekend, y'all.