Came across an interesting episode when Dean and Sam were hunting again after their Dad passed away. They turned out to be hunting for vampires, but man, were we in for a surprise. Both brothers were not taking their father's death well so their relationship was kinda strained.
Dean initially was having the mentality that everything they do, hunting for supernatural stuff, is all in "black and white", "supernatural beings" being the "bad guys" and he confessed to Sam at the end of the episode, much to his own shock that he didn't hesitate to kill those "supernatural beings" and he actually felt good even though some of them might have been human beings possessed by demons.
It only dawned on him that there were actually "gray areas" like anything we go through in life, when the vampires Dean was so bent on catching, and while he was discussing where they could possibly hunt with another hunter, Sam gets kidnapped by the vampires, who told him to let them go because they, unlike the normal vampires, don't feed on human blood. (which helps explain the happenings that led Dean and Sam to this town, the "cow mutilations")
This sort of got Dean thinking whether he had killed "innocent" supernatural beings in the past. As he was raised by his father to hate these "things" and he could just kill them in such an unfeeling way. So I guess we must try our best to think before we act (as and when we can) and not let our feelings rule our actions and most importantly, not to think what we're doing is always "right". Just some food for thought, cheers. ;)
