"Only Now, at the End, Do You Understand"

So, I was watching Return of the Jedi earlier tonight on Spike TV, mostly waiting for the best part (entire scene with Luke, Vader, and the Emperor). There are lots of great lines in those scenes, but one of my favorites is the line quoted in the title of the post (said by the Emperor to Luke, while using force lightning on him). For whatever reason, that line always reminds me of the part in 1984 where O'Brien is torturing Winston, and he is telling Winston that the Party desires power only for power's sake, and that he can make Winston believe that 2+2=4. Both scenes are a) creepy, and b) more importantly, they both have heroes who are finally realizing the brutal and evil nature of their enemies (as in, they are just realizing the true nature and depth of the evil).
Anyways, I'm not sure I have much more to add on this topic, just food for thought.