That, and on the big screen, it evokes big emotions. I was constantly covering my eyes and ears, not because blood and gore squick me, but because it was so hard to watch the character going through it. Leo did a really splendid job in this movie. It might be a little easier on the small screen, where everything isn't quite so much in your face; there were a lot of extreme close-ups.
I have to say about the score, too, that it wasn't anything memorable. Not in the way that it was bad, but in the way it both followed and spurred the action on in such subtle ways that you didn't even realize how much it was manipulating your emotions. There is nothing the least hummable about it, and it probably isn't a soundtrack that you'd want to play over and over, but it was really amazing for how it affected the movie.