In George Orwell's 1984, Winston Smith feels frustrated by the oppression and rigid control of the ruling Party of London, which prohibits free thought, sex, and any expression of individuality. The people of his nation, Oceania, are watched every minute of every day by "Big Brother", an omniscient leader who can only be seen on "telescreens," but never in real life. Winston illegally purchases a diary in which to write his criminal thoughts, and becomes fixated on a powerful Party member named O"Brien, whom Winston believes is a secret member of the Brotherhood, the legendary group that works to overthrow the party. He also begins a covert affair with Julia, a co-worker, which is of course, a terrible crime. In the long run, Winston commits a form of suicide through his actions. Judging by Smith's behavior, he would rather rebel against "Big Brother" as long as possible and accept the consequences for his actions, than fall victim to the Party's control over all thoughts and individuality. .
Even at the beginning of the novel, Winston does not want to sacrifice his freedom for the Party. He purchases the illegal diary and begins writing several questions he has about the people suddenly involved in his life. His mind wanders off to thoughts about the dark-haired co-worker of his, and when he looks down, he sees that he has been writing the unthinkable, thoughtcrime (As it's called in newspeak, Oceania's language). His page has "DOWN WITH BIG BROTHER" written over and over again. He knows that this action will lead to capture and punishment, but his feelings about this Party are too overwhelming to keep to himself. He is trying to express his inner emotions without verbally rebelling against the Party. .
Smith also has views on sex that show his thought that freedom should be granted, and it is terrible to have "Big Brother" watching every action. He's divorced because his wife couldn't produce the baby the Party expects, and wouldn't consider sex for any other purpose because desire is thoughtcrime.