What does Winston's dream, with the girl with dark hair, mean?
The dream of the dark-haired girl in the Golden Country who rips off her clothes with a defiant gesture represents for Winston his desire to defiantly rip away his own pretense of conformity to the Party. He feels no sexual desire for the woman in the dream. Instead, he experiences intense pleasure at her gesture in becoming naked:
With its grace and carelessness it seemed to annihilate a whole culture, a whole system of thought, as though Big Brother and the Party and the Thought Police could all be swept into nothingness by a single splendid movement of the arm.
As we know, Winston wants very much to rebel against the system that oppresses him. He has started the process through buying the diary and actually writing in it, an act he knows will probably lead to the death penalty. The dream of the woman is a continuation of his thought crimes.
Interestingly, too, the dream very closely mirrors reality when he secretly meets with Julia for the first time out in nature after they both listen spellbound to the song of a thrush:
And, yes! it was almost as in his dream. Almost as swiftly as he had imagined it, she had torn her clothes off, and when she flung them aside it was with that same magnificent gesture by which a whole civilization seemed to be annihilated.
It is no wonder that Winston falls in love with this woman. She is almost literally his dream come true.
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This dream represents Winston's longing for a better world, a world without the Party and its absolute rule and suppression of individuality and natural instincts.The girl with dark hair, Julia, appears in the dream as Winston is secretly attracted to her. The way in which she sweeps aside her clothes not only testifies to Winston's desire for her but also appears as a gesture of defiance and rebellion and this is indeed the kind of character that she turns out to be in real life. 'Ancient time' refers to the time before the Party and all its ruthless institutions were formed.