Obviously, this needs to centrally be about the concept of truth beyond this one story.
If you'd like this to be a separate page from lower-case truth, please disambiguate.
Talk about it here.
Despite having only been in control of humanity for six months, the monks broadcasted this false history to brainwash humanity into believing that they had been guiding them throughout human evolution. The broadcast was amplified by statues of the Monks, erected worldwide at the time of invasion.
Despite this, some humans still remembered the real truth. Truth was therefore enforced by the Memory Police under the Memory Crimes Act of 1975. Anyone discovered speaking out against the Truth became a memory criminal and could face a sentence of 10 years in a labour camp. (TV: The Lie of the Land)