What I found most remarkable was that despite NK's best efforts at total and complete isolation of the prisoners -- Shin was born into the camp and knew nothing of the outside world -- the human soul still inherently wants to be free. You can "nurture" a miserable existence all you want but it won't keep.
And in the end, what cracked the walls of the prison (metaphorically speaking) was an outsider with nothing more than stories.
No wonder dictatorships fear things like free speech and dissidents. Even the slightest hint of a better place (through words alone) can start the chain reaction.