"Comrade Ogilvy, unimagined an hour ago, was now a fact. It struck him as curious that you could create dead men but not living ones. Comrade Ogilvy, who had never existed in the present, now existed in the past, and when once the act of forgery was forgotten, he would exist just as authentically, and upon the same evidence, as Charlemagne or Julius Caesar."
I can not imagine doing Winston's job. To know something, to have proof of it in your hands and then replace it with a complete fabrication and destroy all evidence that the they made up story is not the truth. That is the ultimate doublethink, changing something one's self then having to believe that your made up story is reality. The destruction of the past is, to me, one of the most frightening of the many horrific things the party has done. If you do not know your past then what do you have? If you can't trust your memories, what can you trust? The party that's who. They take away your trust in yourself and then tell you that if you follow the party everything will be OK, that Big Brother will take care of you. It's hard to believe that all the people of Oceania would accept this, the constant changing of their past. Although if you think about it for a moment you can see how it would be easier and safer to simply believe what the party is saying. If you don't want to be tracked down by the thought police and tortured it would be wise to forget everything you remember.