Tom Heistuman writes: There are people in the world who are exceedingly good at what they do. Some strive for perfection in such a complete way that every other part of their life suffers for it. The devotion to any activity that requires near-absolute daily focus and attention must take a toll on a person, be it physical or mental. Black Swan devotes almost all of its attention to the mental repercussions on a ballet dancer, Nina Sayers, and it strives for perfection just as she does. It comes very close.