Beautiful, and lyrical, and flowy, and of course Dean was going to capitulate - like he's ever said 'no' to Sam. Pfft.

so Sam humors him, knowing he'll eventually get his way because it's all he's ever known – Sam asking for something and Dean giving it whatever the price might be, and yeah, Sam knows he's a selfish bastard, but it doesn't keep him awake at night.

I kind of like that this makes Sam sound like a total asshole, but it's not like he's wrong.