What is the significance of 1984 plot structure broken up into 3 sections?

Three is a Magic
Number:

• 3 act structure: beginning (problems),
  middle (climax), end (resolution)


• 3 geographical
  settings (Oceania, Eastasia, Eurasia)


• 3 types of people
  according to Goldstein's book:

readability="17">

Throughout recorded time, and probably since the
end of the Neolithic Age, there have been three kinds of people in the
world, the High, the Middle, and the Low. They have been subdivided in
many ways, they have borne countless different names, and their relative numbers, as
well as their attitude towards one another, have varied from age to age: but the
essential structure of society has never
altered.

• The three
  slogans of the Party:

1. WAR IS
   PEACE


2. FREEDOM IS
   SLAVERY


3. IGNORANCE IS
   STRENGTH

• 3 main characters (Winston,
  Julia, O'Brien)


• 3 is often used as a literary device to
  provoke a feeling of unnaturalness, as twos are much more common in nature (limbs,
  hemispheres, eyes, etc).  We realize that O'Brien is third wheel, unnatural.
  


• 3 verb tenses: PAST, PRESENT, FUTURE.  Winston has a
  hard time distinguishing one from the others.


• The Party
  has rolled out nine "3 Year Plans"


• 3 political prisoners
  (Rutherford, Jones, Aaronson)