The only thing he's ever known is now laying dead. That line hits different when you've actually been there — not in the apocalypse, but in that moment after loss when the shock wears off and you're just standing in what's left. The silence in this piece isn't the shock of something happening. It's the silence after you stop expecting it to un-happen.
I recognize that part you don't say: the way your body won't move even if you wanted it to. Not because you're broken, but because every direction ahead requires letting go of the last thing that made sense. The survivors going forward — they've already made that choice. But he hasn't yet. He's just sitting with the fact that the choice is coming and it will hurt either way.