I took on the task of quantifying and defining Primer because I felt Shane will never do so. As the creator of Primer, Shane does not need to examine and explain the minute details. He has had to perform this task twice; once in writing the script and again in editing the film to insure it was consistent with the timeline. This means that Shane can never view Primer from the perspective of the first-time viewer. He cannot imagine the aspect of being puzzled or dumbfounded as the film reveals its complex web of timelines. While Shane knew he was creating an enigma, he has said that he never thought that viewers would find Primer impossible to unravel.
We should be grateful that Shane did not dumb-down the film to the point where every detail was spoonfed to us. The only detail that Carruth has given in his interviews is in relation to TGI. Shane explains that Granger is suffering from recursion. The fact that he has an interaction with Abe and Aaron from the past may mean that now no one will tell him about the machine. Shane says that it is impossible to define exactly how Granger finds out. Carruth says he did not determine the details behind the scenes for this particular part of the script. It is not clear whether Granger’s future is erased because of Abe’s use of the fail-safe or if Granger interacted with the very person who would tell Granger(1) about the box before that event occurred. Granger(2) did not insure that Granger(1) would find the box in the timeline that his trip created. Without that information, Granger(2) becomes a paradox. Granger(1) was sleeping comfortably in his bed at home.
(As an addition: in an interview in France, Carruth has admitted that the narrator’s phone call "could only logically be Aaron(2) talking to Abe(1)". The interview is only available in French.)
