Theory:
Pinkie Pie is the true main character, and the world we see in MLP:FiM is all a figment of her imagination. Not only have we seen her break the 4th wall, we have seen her true insanity in Gummy's birthday party episode. My theory is that Pinkie is truly insane, or the only survivor of an apocalyptic event, and she creates everything around her, the ponies, Equestria, everything, as a "security blanket", so she doesn't have to accept the truth (that she is the only one left alive). Her extreme hyperactive behavior is her trying to distract herself from the dark truth.
Theory: Pinkie Pie is the true main character, and the world we see in MLP:FiM is all a figment of her imagination. Not only have we seen her break the 4th wall, we have seen her true insanity in Gummy's birthday party episode. My theory is that Pinkie is truly insane, or the only survivor of an apocalyptic event, and she creates everything around her, the ponies, Equestria, everything, as a "security blanket", so she doesn't have to accept the truth (that she is the only one left alive). Her extreme hyperactive behavior is her trying to distract herself from the dark truth.