The mood set by the pacing, cast, visuals and audio, its so engrossing!
But my enthusiasm aside, be careful, here are what I consider to be some important considerations when you are preparing to watch it.
1>Watch it ALONE at least once, especially the first time.
Also, while we do have a nice home theater system in the living room, I watched this with home theater headphones cranked up to really bring myself into that world.
2>Expectation going in -If you are looking for a movie that spells it out in familiar letters that everyone can see and talk about, you'll probably be painfully bored.
You have to meet this half way, in terms of audience effort its more like a painting than a film. The movie definitely puts you on a suggestive path where the mood, minimal dialogue and situations give plenty of room for your own powers of perception and interpretation to engage, which have hopefully been sharpened by your interests in human nature and history.
3>Energy level and frame of mind -I made the mistake on my first attempt to watch this late at night as a second movie. I had to stop a little less than half way through. So my recommendation is to watch it earlier than later in the night, when you are in one of your more reflective serious moods. And if you are going to indulge in legal intoxicants to 'expand your mind', it can enhance the experience, but drink responsibly.