Sam Winchester understands what they experienced in purgatory most in the little things. The little things are what reveal the most, he knows. Like when they are in motels, and Dean relishes in the comfort of even the dingiest of beds. It’s in his haughty laugh and his stupid jokes- it’s in his insistence that the crap bed beneath him just has to be a temperpedic that Sam can tell he spent days struggling to rest in the most painful of places. It’s revealed to him when Dean returns from a quick run to the store or from a hustle at the nearest bar, Sam watches Castiel’s face brighten in the reassurance that Dean has returned to their side yet again, the younger brother knows there were too many moments of doubt. That the angel whole-heartily feared that Dean would not return from whatever doom he walked into far too many times for his body not to commit the slump of the shoulders, the sigh of relief, the warmth of his features to muscle-memory.