In the beginning of 1984 Winston thought that there were things that he knew to be true and that the party and Big Brother couldn't change. However, when he was taken to the Ministry of Love, he learned that the party could change the way he thought. In the beginning he had memories of his childhood. He said that he knows that 2 + 2 = 4 and they can not change that. He thought that as long as he remembered what it was like before Big Brother took control and he knew things that would never change, then he would still be in control of his mind. After he was arrested and taken to the Ministry of Love, he was tortured and they tried to change him but at first he resisted and after his torture he still hated Big Brother. He was taken to room 101 where he was forced to face his worst fear, and he eventually gave in.
He told them to put the rats on Julia, when before they were arrested, he said he loved her and he would never leave her. Once he was released from the Ministry of Love, he was stripped of all the feelings and emotions he had before. When he saw Julia, he had no feelings for her anymore. When he was sitting there thinking, he started to remember when he was younger and he played a game with his mother and his sister. Then he said it was false memory and that it didn't really happen. Big Brother took away his memory. He took away the things that Winston thought would keep him in control of his mind. When he was sitting in the Chestnut Tree Cafe he wrote 2 + 2 = 5 with his finger in the dust on the table. That showed that Big Brother changed what he knew was true and what he thought Big Brother would never be able to change.