against cured
You can't drink legally in the U.S. until you're 21. I mean, there are ways of getting around it, but you do sort of have to jump through hoops a bit. So when you turn 21 it's a BIG DEAL and you get really drunk with all your friends. I lived there for a while from when I was seventeen until I was about twenty-two, so I got to experience the big American 21st b-day. Didn't really make-up for the whole suddenly having to follow stupid culturally inapplicable laws, but it was still pretty good.
Happy birthday, then! Probably a good idea to hold off on the celebrating. I take it they're not big on that.