Seems to be a song about a duplicitous lover, or perhaps somebody who's left the narrator behind. It spins the idea of Cinderella going from rags to riches and suggests she rejected her past and all the people in it, fully indoctrinated into the upper-class. But this could be one of those classic unreliable narrator situations - why would Mrs. Cinderella pound on their chest, or knock down their door if she wants nothing to do with them? It seems like she's trying to communicate and possibly reconcile but the narrator has rejected her completely. There's a sense of self-deprecation and irony in the lyrics - perhaps the narrator does not believe they can keep up with her cosmopolitan lifestyle. Ultimately this song centers around how class or perceptions of class can drive people apart.