Yeah, that was a painful moment. But it really just showed the parallel to Sam's own attempt at normal, doesn't it? So Sam got his Mom's dreams but his dad's obsession with vengeance, while Dean got John (and Samuel the elder)'s drive to hunt and John and Mary's penchant for making deals with demons to save family members.

Oh, Winchesters. You are merely pawns in the game of life apocalypse.