Winston recalls a happy day he had spent with his mother and baby sister. Suddenly, his mind decided it was a false memory.
He was troubled by false memories occasionally. Winston had been brainwashed to label happy memories of his past as false. Anything in his past which gave him any pleasure had to be false.
His mind had been so corrupted by the torture than he polices his own mind. Winston tells himself that Some things had happened, others had not happened.
And leaves it at that.
The extent of the Winston’s corruption by the torture is slowly exposed. How his own mind becomes the ‘thought police’ where he is not allowed to think of certain things, to discard thoughts, to program himself to behave as he is ‘supposed to’.
There are no eyes on Winston, no one cares what he does, because he has become his own warden.