|"Would you like to read my Lyra/Bon-Bon adventure 'fic?"|
As I've mentioned, I find FiM's world to be really fascinating. The show rarely goes into the history of the setting, but a lot can be extrapolated from the things we know and occasional glimpses into the past. The story of "Hearth's Warming Eve" shows us that, long ago, the earth ponies, pegasi, and unicorns lived in separate and culturally diverse realms. They eventually united to found Equestria, and some indeterminate time after that, Celestia and Luna came to rule it. During their reign, they came into conflict with a chaotic demigod named Discord and sealed him in stone. And, eventually, Luna was turned to the Dark Side by a shadowy force known as "Nightmare" and launched an ultimately failed coup against her sister.
|Behold, the savage beastmaster.|
These questions aren't likely to be addressed within the show itself. Some of them might be, eventually; the answers to almost all of them are, apparently, contained in the show bible Lauren Faust created several years ago. But for every question you could think to ask, you can bet that a fan of the show has already come up with an answer, and some of those answers might be better than even Faust's.
Quite frankly, from a world-building perspective, fanfiction is magic.