What are some achievements of teenagers?

Doing well in school, for one - as this allows for a greater number of opportunities in the future (such as college, a better job, less stress paying bills later in life, etc.). Also, teenagers have brains which possess faster speed of information processing. They learn more about computers and games, and at a quicker pace than adult. Teenagers who learn the value of networking with others also have more enjoyment in life, as well as more opportunities in the future. These are just a few examples among many!

Some teenagers have started successful enterprises (from google to Facebook, and many more).