What is this film point?

Rating: 2/10 (1 December 2006)

I don't get the point. It makes you ask yourself, "so what?" after watching it.
All the characters fight each other, but the final minutes of the film are so inconsistent. Why all the come and go of the final scenes? Did Matt Damon character didn't remember the chiefs assistant, the one that finally kills him? Why Damon didn't kill her girlfriend, as she knew his secrets? How come that they don't suspect in the police department about him?
I feel that the director wants from is just to see the film and go home, not to watch it with a bit of attention.