the time in life when you awake from adolescence. usualy about the age of 19 to 25. you may still have a headache from your teenage kicks of the past, but in whole you are pretty lucky to become a real man or woman. its maybe the coolest time because you realize that you now are a twenty-something (a sexmachine in a cool outfit) and the opposite of a teenager (a whimpy wannabe).
common changes: better taste in music, better clothes, better sex, going to college or earn own money, less acne, less teenage angst and coming to the conclusion that those realy popular kids who bullied around in highschool are going to be the ones with the most boring/fucked up life.
as long as you are in highschool you can't see that there is a life after this twilight zone... but hell yeah there is! wait until your post-adolescence