Being a positive influence on future generations is more important than you may notice. However, that's because you're thinking on the surface. Yes, the targetted age to be the most influential is in your 20s. Yes, your 20s are scripted to be your 'selfish years,' but instead of being the "basic" 20-something, step outside the box and use one of your biggest strengths: your influence.
In your 20s, you are still considered cool enough to connect with the youth but old enough to know a little something about something. You're crossing the path, or just crossed the path that teenagers currently agonize over. Life after high school to be specific.
The youth are the future as are the millennials. Let's do our part to make this a better world for generations to come.