This is going to sound entirely cliche, but here goes:

Do what makes you happy.

Sometimes you just have to say a big "fuck you" to everyone you know and go and do something that you want to. There's nothing wrong with abandoning responsibility for a while and taking off if that's what you want to do (although you should probably make sure that you don't have kids or a dog or anything that might die while you're gone). It might sound awful, but sometimes you've just got to be selfish and do something for you, and just for you.

I hate that my answers always sound so sappy and bullshitty, but that's just the way it is, I guess. Go hook up with some stranger in a bar or buy a plane ticket to anywhere. It's possible that you might regret it later, but at least it'll be a good story. Plus, it's nice to get that stick out of your ass every once in a while.

Admit it.