The infamous you’re already dead linefrom Famine; latched onto, and embraced as evidence that Dean is dead inside. And more specifically, that he fucks and eats and jokes all in the name of covering that up, because that’s the only way he can feel anything, even if it’s just for a moment.
Because Famine said so, so it must be true.
In actuality, the theme of Dean and that yawning hole inside him was put into our minds a season before, right after Dean got back from hell and he was feeling overwhelming guilt for what happened there.
And then we learn where it actually started: after John died and Dean felt so much guilt that he wished he had gone with Tessa the reaper.
So we have a man laden down with guilt and self-loathing, tangled up in how he feels he failed his father, failed Sam and failed to resist thirty years of torture. Not a man who feels nothing at all.
In Season five, when Famine comes to town, we have a man who’s dealing with all of those same feelings, along with the fact that he feels Sam betrayed him, Sam’s demon blood addiction, new feelings of failure after Alastair told him he failed in hell where his father prevailed, and trying to avoid becoming Michael’s vessel. Along with all of that, Dean is trying to stave off the freaking apocalypse. So yes, Dean is dealing with a lot. Dean is sinking toward depression, and he’s hurt and he’s running out of hope. But none of those things mean Dean is dead inside.
He’s a man filled with grief, guilt and self-loathing because of everything he’s been through; because of all the weight that’s been put on his shoulders.
Being empty inside, with hole in your gut is a metaphor for that. It doesn’t mean Dean doesn’t find pleasure in things like his cheeseburgers and his rock music; his car and his ride on Larry the bull. It doesn’t mean Dean fucks to try to feel something.
He didn’t start feeling that hole in the gut sensation until John died, so what was he doing before when he had no gaping hole to fill? The same as he’s doing now: enjoying life where he can, because his life is not a barrel of laughs otherwise. So when Dean finds something he enjoys, he puts everything into it. He continues to do that even when circumstances ramp up his guilt and self-loathing.
But most importantly: Famine is a being who delights in the suffering of others. So, why are we taking his words at face value?