The song is about her--i.e., the singer--whose sense of identity and self-respect has been wounded by her association with the megalomaniac. He's so vain he doesn't understand that the song is about her ability to finally assert her pride and self-respect. Instead, he only sees that it talks about him. A good analogy is Gone with the Wind, which although it centers around Scarlett, is really about Rhett, and his discovery of his own indepenendence.