Rainbow Dash moved into Ponyville's Cloud House on her birthday. She never expected things to turn out like that; it's a long way down from Cloudsdale, after all. But like so much else in Rainbow's life, Fluttershy had a great deal to do with it. Not that her shy friend could have known that when she made a single choice long before.

"Home is not where you live but where they understand you" — Christian Morgenstern

(Note: Written long before "Flutter Brutter", so don't expect it to mesh with current canon.)