How does the past Oceania differ from the present Oceania in 1984?
In 1984, it is very difficult to compare the past Oceania with the present. While we can state that there were no telescreens or ministries, for instance, it is almost impossible to make any other comparisons because the Party has rewritten the official history in a way which glorifies Big Brother and the revolution which brought him to power. Here's one example from a history book which Winston reads in Part One, Chapter Seven:
"In the old days (it ran), before the glorious Revolution, London was not the beautiful city that we know today. It was a dark, dirty, miserable place where hardly anybody had enough to eat and where hundreds and thousands of poor people had no boots on their feet and not even a roof to sleep under."
Winston tries to confirm this view by speaking to an old man in the Prole district but he soon realises that he is wasting his time since the old man remembers nothing of any real importance. Moreover, to exacerbate the problem, Winston's own memories of the past Oceania are distorted and fragmentary. In one flashback, for instance, he remembers spending the night in a tube station because of an air raid. In another, he remembers the last time that he saw his mother.
By making it impossible to obtain accurate information about the past, the Party demonstrates that it is powerful enough to rewrite history while also controlling the present and the future.
In George Orwell's 1984, it can be a little difficult to envision what Oceania was like before it evolved into its totalitarian state. However, it's possible to get a basic idea of what Oceania looked like before the events of the novel. In its past state, Oceania was not a single nation, but was a diverse geographic region composed of many nations, including Great Britain and the United States of America. Indeed, in the novel Oceania comprises what was once the Americas, Great Britain, Australia, and more. The major difference between past and present Oceania, therefore, is that the past Oceania was composed of many governments, cultures, and languages, while the present, totalitarian government of Oceania presides over a standardized region that is oppressed by a single, tyrannical government. Once the reader understands how vast the present Oceania is, the horrible nature of Big Brother's conquest becomes even more pronounced.