Why it's great to be a sixteen year old girl

It's great to be a sixteen year old girl!

I'm writing a story by that title. It's based in the post-scarcity future. She will be using her Santa Clause Machine to make a party dress for her sweet sixteen birthday. She has a boyfriend who is just enough older to be exciting. He will be helping her plan her party.

Both she and her boyfriend have attractive flawless bodies, and that isn't at all unusual in this utopian future.

So, why is it great to be sweet sixteen? I need ideas. The reasons can be serious, sweet, or silly.