If having to own up to the fact that your parents are no longer legally responsible for you, well, then it is indeed a sad day!
But I suspect that is really not an issue.
You are now the target demographic that every corporation is vying for and marketing their products to...
...your voting strength in numbers is unprecedented...you have the power to sway policies and what candidates get into office!
You are at a sexual peak, and women (young AND old) crave your attention.
In a year, you can legally purchase alcohol, and you can make practically any decision you wish without parental approval!
You can cheaply and aggresively invest in one or more funds that will allow you to live comfortably during your retirement years.
You are a couple of decades away from being concerned about health risks due to age and excessive consumption.
There is more, but you will find out about those soon enough...after all, this is a time for discovery, not past regret!
So enjoy! Many of us here that are greying around our temples only WISH we could go back to your age...and probably change the way we did a few things in our lives!