It is a song of encouragement but it's full of double entendres to be sexy. The horn is tooting your own horn. Cream is like cream of the crop. On top is your personal best (in Prince case, number one). Make the rules and breaking them all because you are the best is simply fantastic because it reminds me of William Shakespeare. He invented the sonnet (not the italian one the other one). He made the rules. On top of having the ABAB CDCD EE rhyme scheme, each line was supposed to be 10 syllables. That's the rules. Except for the rare exception where he breaks the rules and throws in a 9 or can 11 syllable line! Why? Because that line is extra important, pay more attention to it please! He broke his own rule because he was the best. "How do I love thee?" Is a famous one...

This is Prince basically saying I'm your eras Shakespeare, deal with it. I mean he had to know that little tidbit about the sonnet right? Also the message is for a wider audience to grasp their inner awesome.

I hope this helps and I hope this makes you analyze other lyrics of his. Like when. Does he break his own. Rule in the song? Those are important lyrics! Look at them!

I love the song and P saying he wrote it while looking in the mirror was hilarious. Whether true or not who knows, but it lifts my spirits when I hear it and that's why I love it and so much of his music.
On the subject I have always wondered who other certain songs were about (if indeed they sre about anyone in particular). For example: International Lover, Insatiable, Adore. Does anyone know?