Probably some teenagers have done important things. I don't expect them to have a long list of accomplishments (or even the same is true of most adults), but I

Probably some teenagers have done important things. I don't expect them to have a long list of accomplishments (or even the same is true of most adults), but I am also not going to denigrate or take away from their experience with phrasing like "ain't done jack squat". Seems unnecessarily angry, and like a put-down.