Well...
The stereotypical prima donna is conceited, stuck up, and thinks that she's very important.
Peter Gabriel's song is about someone who is conceited, stuck up, and thinks that he or she (the gender is not obvious in the song) is very important.
Cheers,
Ben
I have come to believe that idealism without discipline is a quick road to disaster, while discipline without idealism is pointless. -- Aaron Ward (my brother)