Cultivating Scepticism and Inquiry
Almost everything you know is a lie. Some of it is the product of lazy thinking, passed on by those with no critical thinking skills. Still other information has been deliberately manipulated and falsified to suit somebody's agenda. Those who simply accept something and regurgitate it to the next person, spread the lie like a disease. And as long as a lie fits well into the established worldview, however confused such may be, it will encounter few barriers and spread quickly. The truth, dangerous to those in power and threatening to your perceived reality, will be resisted at every turn.
With very few exceptions, and unless you had exceptionally enlightened parents who among other things did not send you to school for indoctrination, then most of what you consider to be self-evident, and beyond close examination - in other words conventional wisdom, is going to be false. Think of it like this: if the knowledge came to you cheaply and easily, if you didn't work hard to research and evaluate the opposing schools of thought, if you didn't spend your days reading and your nights thinking about it, and if a significantly large number of people agree with you, then it's probably wrong. Phrases like "we all know" and "it's a well known fact" usually precede utterly fallacious statements.
The trick is in approaching all information with skepticism. Not just new information, but old, ingrained ideas too. Those are often the worst culprits. You can easily spend more time unlearning old falsehoods than learning new truths. In many cases the latter is impossible to accomplish until the former is well underway.
To do so, you must have varying degrees of trust assigned to knowledge, based not on the authority of the person originating the idea, but on its logical viability, together with your own research on the topic. Research that must be undertaken with the knowledge of all the common human pitfalls, from logical fallacies to confirmation bias. Only when we know how we tick, and how to tune our lens appropriately, can we hope to begin uncovering the truth from underneath the pile of lies we have been taught to believe our entire lives.
Nobody said it would be easy. "The truth will set you free, but first it will make you miserable."