After being accidentally transported to Equestria, a series of happenstances netted you one request from Princess Celestia herself. Why did you choose to have tea?
An extremely private and important meeting is taking place in Canterlot among some of the most powerful figures in Equestria. And also you for some reason.
After ending up in an Equestria ruled by Nightmare Moon, you somehow became the tyrant's favorite subject, while she somehow fell in love with you. Maybe there is something more to her hidden beneath that cruel exterior.
While getting adjusted to your new life in Equestria, you take it upon yourself to learn how to use magic. As it turns out, this is harder than it sounds, especially considering you're a human.