Why don't they know?

In Fahrenheit 451 the past is completely erased. How do the people not know anything about the past? The people could be brainwashed into thinking their society was always like this. In their society books are illegal. Some of the books describe the past, which could change the way the people think about the past. Right now the people don't think about the past because they were told to think it was the same. By making books illegal the government can stop the people from knowing about the past. The government also controls the education of the people in the society. Education makes us think and question things, but the people in Fahrenheit 451 were taught that their past was always the same. Their most effective method in keeping the society from knowing about the past is education. The government can control what the people know and learn. Also the activities that are in the society are effective because if the people are busy then they won't have time to question or think about what they are being taught. For example, Montag's wife Mildred enjoys talking to the television which takes away time for thinking. She is so busy with the television that she doesn't have time to think about other things like the past. In school the people play more than they are taught. Beatty was explaining this to Montag in a lecture he said "School is shortened, discipline relaxed, philosophies, histories, languages dropped, English and spelling gradually gradually neglected, finally almost ignored. Life is immediate, the job counts, pressure lies all about work."(55). Many of the subjects were dropped, so the people would play in school. If the people aren't learning then they won't question how the society used to be. All of these things contribute to the people not knowing about how the world used to be.