What are the "cool kids" doing at each of these age ranges?

Define cool as you want but I define it as being the kids that most people from each demographic either look up to or somewhat want to be like. We'll skip high school and start with college and life after it.

I would ideally like to confine this to the USA but other nationalities can share their experiences too. Just specify if you aren't American. I have great knowledge of what the kids at the 18-22 age range are doing but I won't say because this is a question and if I knew of all of these age ranges then I wouldn't have asked.

18 - 22 :

23 - 30:

30 - 35: