Way to make me feel like a damn old bag, man. But yes! There are a ridiculous amount of teenagers on Tumblr, but there are bunch of them in their twenties and thirties (and even forties). I recommend withoutmelissa.tumblr.com, nogreatillusion.tumblr.com, buildingaladder.tumblr.com, capucha.tumblr.com, thatwhitebitch.tumblr.com, drinkyourjuice.tumblr.com, daveholmes.tumblr.com, and nedhepburn.tumblr.com. And a billion more, but that's a great start.