Luna was saved by the Element of Harmony, but found life after rescue more difficult. The ponies ignored her, with the memories of Nightmare Moon still fresh in their minds; besides, after a thousand years of silent solitary life, it was difficult for her to adjust to the bustle of Equestria.
Change is never easy, and even with the help of her sister and new friends, Luna continues to struggle, failing far more often than she succeeds.
Perhaps self-imprisonment on the moon is Luna's true hometown.
Cp: Luna×Twilight Sparkle
Long story, unstable updates
Motto: Friendship is magic