Re: Trust nothing, check your data, use various sources.
What has changed to some extent is which authorities people believe in, although most people still believe the main messages put out by their own governments. And it is still true that the bigger the lie, the easier it is to get people to believe it. It's not only specific events and widely believed facts that you should question, but also various core beliefs that are taken by most in Western countries to be beyond controversy. Such as democracy being the best form of government. And the Western notion of work-ethic (hard work should be rewarded, it is generally wrong to get something without working for it, and laziness has bad consequences). Both beliefs being contradicted by many facts that show the opposite is frequently true.
Almost everyone these days believes that slavery is abhorrant, yet fails to see that things really have not changed at all since the days of slavery other than the ethnicity of the slaves - it's just been re-named and disguised. There is little difference between forcing people to work for no pay (but providing them with necessities to keep them alive), and giving people Hobson's choice between being penniless and homeless or working hard in return for a wage that will just about pay for food, clothing and shelter. "Freedom" for the a huge proportion of people is the biggest lie of all - but they believe it.