I hope that not only my documentaries, but everybody's documentaries, last. It will really confuse historians in the next century, because they'll have, in addition to all the print material, they'll have all these pictures to look at.
You have to edit the material. That assumes that some kind of a mind is operating in relation to the material. Not all minds are the same. Every aspect of filmmaking requires choice. The selection of the subject, the shooting, editing and length are all aspects of choice.