Winston Smith grew up with one sets of norms for the first eleven years of his life and then moved to another. In his early life, though economically deprived and always hungry, he lived in a family with his little sister and a mother who loved him dearly and was willing to sacrifice for him. After his sister and mother disappeared, he was raised as an outer Party member. As an adult Party member when we first meet him, he is filled with fear, hate, and violent fantasies. He holds others, such as the Parsons and the proles, in contempt, and he loathes the Party. He wants to rape and harm Julia. This second personality is a product of the Party.
When Winston meets and falls in love with Julia, he develops his humane, loving side. He wants to sacrifice for Julia, and he comes to see the fat, old prole who hangs laundry outside his window as a beautiful human being. He remembers and dreams more and more about his mother as Julia triggers memories of the love he experienced as a child and which is still buried inside him. He finds too that humanity resides in the simple rituals of two people who love each other doing ordinary things together, such as drinking tea and talking.
The new person Winston has become, however, is anathema to the Party. The Party can't tolerate him being loyal and loving to another human being. It can't bear him being happy, because his happiness means it doesn't have total power over him. It wants him in a complete state of abject loyalty to Big Brother. When he is arrested, the Party, though O'Brien, uses torture to try to eradicate every vestige of humanity from Winston, so that he is nothing more than an empty shell.
Winston represents, therefore, two very different beings: the ever fearful, ever angry creature the Party has wrought and the caring, compassionate self brought forth from being loved by his mother and Julia. The Party almost wholly destroys him but never fully eradicates the loving self, because in the moments before he dies, he remembers a happy time playing a game of Snakes and Ladders with his mother, a memory completely divorced from anything to do with the Party or Big Brother.