The story is insightful, heavy on philosophy, extremely ambiguous, and digs into interesting questions about a very viable future technology. On a superficial level one can take the ending (which does provide closure) at face value, but it was intended to make one think. It's based on a Philip K Dick short story, "We Can Remember It for You Wholesale", and it shows.
It's a grandiose story, but only on the surface and only due to the fact it's set in the future. The plot is something that will affect everybody at some point. If you haven't seen it yet, I'd strongly recommend going in blind.