Well, I'm still close enough to the Twenties to hear the music thumping, though I don't always know what they're talking about. (Case in point: Had to ask some buddies what "cashin' out" meant, since I just know it as what I do when I'm ready to leave the restaurant.)
Thirty-one feels miles away from 30. If I met someone today who was turning 30, I'd probably say "Awww!" as if they were turning five. Weird.