In high school, teens may have more opportunities to join school clubs to gve them more experiences in a wide variety of areas. Because they are developing their interests, they may join a lot of groups to try out many different skills. To outsiders, it may appear as though teens are too busy and suffering from the stress of too many interests. It's important to remember that it's developmentally appropriate for teens to be experimenting with different clubs, diferent sports, and different hobbies. It is normal for them to try out as many as they have interests in and then settle down to what really appeals to them.
Nothing's the same.
In American culture, adolescence is getting longer. It used to be from 13 to 18. With medical advances and the extension of higher education, the period of adolescence can range from 11 to 18 on up to 22. And teens have to be in different roles at different occasions. For example, while they are not considered adults for using tobacco or voting until they are 18, they are able to get a driver's license at 16, but can't drink alcohol until 21.