Legend of Zelda Twilight Princess - problem with returning to the game after end credits?

So I finally got around to finishing Twilight Princess. I watched the end credits, eager to get back into the game to find my last poe soul and finish some other orted side quests. But after the "the end" screen disappears and I re-open the file I just finished playing through, I'm returned to the beginning of the Hyrule Castle dungeon, Midna still by my side. I'm fairly certain that the game has registered my killing Ganon because the hearts I lost during the final battle are still gone. But is my returning to the castle some sort of glitch, or is it impossible to return to the game to a point where Ganon and Midna are gone?