[He huffs, like Shinn had said something funny. It's the ghost of a laugh, in part because anything louder would probably make his head hurt worse (again), and in part because-

Because. Because because.]

I'm an idiot, you said it yourself, and the thing about idiots is that we're really resistant to dying. Probably 'cause we screw up often enough before we can get to death that it's tough to put a dent in us.