Unless like you already drink enough that a 21st birthday doesn't matter, it definitely does matter. You said you're not american, so it might not be celebrated the same, but just think at what being 21 means. You can legally drink alcohol and not get arrested (yeah, legally).
You don't have to get shit faced, though you should. You can go out and buy the first round (even if you won't be drinking) and feel like a boss. It's something you've had to wait for your whole life, so celebrate it.
oh, and OP beat Rush. Haven't seen that before. Cry Rush!