The answer is:

Because there will be flowers, John, that only you can pick. Butterflies that only you will see. Laughter and tears that only you will know. And dreams that only you can dream. 

The question was: 

How does one know if they really are a prince or a princess? 

Good question, your highness -
  The Universe
I teach a LIVE mini-workshop every Tuesday, and they are POPULAR!

Tomorrow I’ll be talking about creative visualization and concentrated thought… followed by BREAK-OUT groups to meet like-minded peeps!

Thoughts become things... choose the good ones! ®
To reprint, credit and attribution to ©www.tut.com 
Sometimes, John, you make my heart melt.