Another book I really enjoyed was 1984 by George Orwell. Where everything, even reality itself is controlled by the Inner Party. Nothing can be made sure of. The date, time, historical facts etc are all subjective and can be changed at the desires of a few powerful people.
The book really made me think, which is something I like about a good book. If everybody thinks they see something or hear something or even grasp something in their hands, who is to say that doesn't actually happen? Is there any rel world outside of the mind, and if so how can it be proven to exist? The senses are connected directly to the mind, but the mind can be fooled and documents can be changed.
The part that stuck with me the most though was just how similar to our present day the book seems.
An example: gas prices.
People seemed to be overjoyed whenever they dip down slightly yet forget they they continue to gradually rise. "I'm glad it's only $2.97 here instead of $3.00" then later "I'm glad it's only $3.15 here instead of $3.20"
Maybe I'm just a cynical person, but it just looks like most people, not all but most, take tings on face value and will not only believe what they are told from their government and other authority figures, but will defend it. I'm not saying to disbelieve everything you hear, just you know...be wary or things.