Rainbow Dash naps a lot. Every day, several times a day, she can be found sleeping on clouds, or in trees, or even, very rarely, in her own bed at her house. And she always seems to have so much free time. Does she ever do any work?
Princess Celestia was quite clearly overworked lately. Twilight just had to find a way to help. Unfortunately, the only answer she found was a bit odd.
My name is Sunset Shimmer. I am the strongest unicorn in all of Equestria, and my life is over. I'm in hiding and on the run, and I have no idea where to start putting things back together.
The princesses gave their magic to Twilight to prevent Tirek from stealing it. As a result, they end up stuck in Tartarus. The fact that things manage to go downhill here says a lot about the wonders of family.
If Ponyville's new repair-pony gets his way, the Mane Six won't even know he exists - and nopony in Ponyville will miss him for long once he's returned to Earth.