When Sam told Charlie he understood now that hunting is his life and he can’t and don’t want to do it without Dean. I come to aware, this is true. Let’s looking back, every time Sam and Dean split up, Dean back to hunting and Sam back to his “own” normal life (except Season 10,I guess this is the season he really understood he will never back to normal). Sam kept getting away from his life whenever he had a chance, but every time when Dean is back, he back to the life he always denying. So, Dean is the reason why he going down this road; Dean is the reason he keeps going; Dean is the reason he embracing this life and enjoying it. And when Hunting become his life, it also means Dean become his life. Therefore, when Dean is over, his life is also over.











