Also, I don't think the concept of doublethink was ever plausible. A person can't edit their own memories.
Um, people do edit their own memories. It happens all the time in real life. Ask anyone who's ever supported a politician who later flip-flopped, or any person who ever flip-flopped themselves. Or, for that matter, anyone who believes in the divine infallibility of the Bible in spite of its numerous contradictions. All Orwell ever did in Nineteen Eighty-Four was invent fake names for real psychological processes.