Regarding what Dream posted, I was thinking about it earlier. I remembered someone said it was done as a joke. Well... it has a very weird sense of humor then. What I mean is that I don't get how you do a song like this as a joke, I'd have thought of something more Lose Control-ish to make a joke.
About the interpretation... I can't help but try to figure out what talks about but of course, we will never know for sure if Amy doesn't say it and I doubt she will.
Then again, its part of the magic of every song.