During the world wars German war machinery successfully manipulated the media (newspapers and radio) to rule over the greater Germany. Even this day counties like China tightly control what information/news reaches the public and what does not. If done properly and consistently over the years, this propaganda can successfully and dramatically change the beliefs, perception and the public opinion. Sometimes even to the extent that young german kids thought they were doing their parents a favor by reporting their activities to the Gestapo.
It was only now I have realized the importance of good education. The more one has access to international media (internet, newspaper, tv etc.) the more international languages one can read and write in, the harder it is for the government to poison and condition one’s mind.
Without access to international media and people with diverse opinions a person will not only be biased. What’s worse is that by accessing only the limited information, they would reinforce their perception. Net result is that everybody has a different view about the same thing, yet they all will be convinced that this is the right view.