Something went wrong in this long film based on the interesting idea of a man who grows old rejuvenating after birth, but could not appropriately be reflected in the final outcome.
Pretentious from the begining, perhaps it is the script that is not strong enough as wanted (and needed) to be to sustain this idea and intention for all it length.
In addition, Fincher has never been seen so distant, where frustration, characteristic shaft of his still short filmography, has been so difficult to perceive in his characters as in his direction.