Grief really is a peculiar feeling. It clings to you, silently. It hovers over your heart, waiting for the right moment to pierce through on a random Tuesday. Memories come back in flashes, a mosaic of moments you thought you forgot about. But you didn’t. You never did. Your mind, that funny place, was hiding it away to protect you.

Dean Winchester’s mind, however, seemed to function differently. Memories never fade, moments keep flashing back every time he closes his eyes. The ghosts of the people he has lost float around him like storm clouds, tormenting him and keeping him awake at night. A constant reminder of his failures to keep everyone he has ever loved safe.

But there’s a blank spot where the ghosts linger. It holds the weight of Castiel’s absence.

Dean can still feel the grip of Cas’ hand on his arm when he shoved him to the side before leaving him forever. He remembers his knees giving out on him as he watched him get taken away by the Empty. He remembers looking into Cas’ eyes for the last time, the lump in his throat – or maybe it was his heart, Dean wasn’t sure – like needles every time he tried to swallow down his sobs.

It ruined him. Cas’ words ruined him. Cas’ ‘I love you’ ruined him. It kept him awake at night, wondering. It added a heaviness in his heart that terrified him, opening up a spiral of questions that Dean might never have been ready to face.

But even if he was, it would be pointless. It wouldn't change their story. It wouldn't bring Cas back. Nothing could.

If Dean will survive long enough, if no supernatural entities get the best of him in the end, the years will pass and all he’ll have left of Cas would be an aching memory. Cas will never listen to Dean’s desperate prayers again, he will never watch over Dean again, he will never tilt his head and pronounce Dean’s name ever again.