Why have the government taken away the ability to gain knowledge, and why are people not allowed to travel outside?

Throughout the novel, the reader is presented with a conflict between knowledge and ignorance. What does true happiness consist of? Is ignorance bliss, or do knowledge and learning provide true happiness? Montag, in his belief that knowledge reigns, fights against a society that embraces and celebrates ignorance. The government can control and manipulate the population by perpetuating ignorance.