I'm in the same boat here: just turned 22, about to start my final semester of college and my life is great, yet I'm in a funk. I think it's a combination of the uncertainty of the future and the "lasts": last time to visit SA and Sacramento for a while (two places I love), last time to be in college, see college friends, not pay bills, etc.
The worst part, though, is the cyclical aspect: Once I realized I was bored/sad/whatever, it just made me sadder. I get frustrated at myself just like you guys are getting frustrated with us "dumb kids" for being bored at such a young age. And yet nothing seems to be turning around.
Just gotta hang in there and start being spontaneous, I guess.
I don't really miss anything music/TV/movie-wise from my youth, though. :P