Not only does the world see you as an even adultier adult-but drinking alcohol is now legal, too! That's big time! (Yes, your 18th birthday technically means you're an official grown-up, but 21 just hits.different, ya know?) So, if you have a person in your life who is about to hit this riveting and, er, semi-chaotic age, we've got the perfect 21st birthday gift ideas for you to choose from that are useful, sentimental, and ofc, party-appropriate. In fact, it might be one of the most exciting birthdays of them all. Turning the big 2-1 is a pretty huge deal.