You don't get it! [He wrenches away, crossing his arms.] You're teenagers. You might not be a grown-up, but you're a lot closer than me. And you can do... stuff.

[Dipper isn't sure he wants grown up stuff now. He's pretty sure in five years he would.]

And when you get older, fine, you could be in your twenties. No one would question it. I'm thirteen today and that's fine, but if I told you I was fifteen or sixteen and I looked like this, would you believe me? And what if I'm stuck for longer than that? I don't want to be in my twenties and thirties and still look like a twelve year old! Growing up on the inside will only make that worse!