Well, as Mark Kermode often says, in 2001 Kubrick went from the birth of man to star-child evolution and did it in under two hours, so no-one else has got any excuse!
In truth, this fits in with my regular complaint, that when adapting anything, the writers should remember they are making a film and start from scratch to consider how they would tell the story in a screenplay. I'm not sure it can be done in this case, but Affleck is a superb director.
