The obvious answer here is that you have not given it enough thought. You have not actively participated in discussions with real people who hold different views and been open to listening to those views. Here is one simple word that answers a lot of what you claim you don't understand: POWER.
Here is a simple way of describing it that involves a huge amount of nuance and complexity behind the scenes -- those who have it want to keep it; those who don't have it, want it. Now, think about what it takes to get that power and how many palms you have to grease along the way. You will be owned by those interests in the future -- how will you pay them back?
Blaming the media is a stupid, currently favored bogeyman approach to keeping one's eyes closed. If you don't trust an "independent" (yes, there are lots of issues with that word) third party, then who are you supposed to trust? Give me another entity that can delve into every facet of government, business and personal life and disseminate knowledge to the entire population? Many countries have carved out specific protections for the media to be able to do this and have given the media unprecedented access just so a semblance of "truth" (ouch, another problematic word) can get out.
Why do you suppose religion exists? Why would people willingly submit themselves to the authority of a small, privileged group (or individual) and then take the word of this group, or person, as (pun intended) gospel? Why don't they ask questions? Why don't they confront their leaders?
One key thing to remember is that the majority of the World's population is too busy trying to survive to be worried about politics, or why wars are started. They are manipulated by the information brokers into believing the cause is just and they don't have time to adjust their lives to accommodate fact-checking the allegations. Those who do have the time are wealthy (relatively speaking) and they aspire to be power/information brokers themselves, even if only in small ways.
At a basic level, we are all the same. We identify with our peers and our community. Our "truth" is built around the place we were born and where we grew up -- even today. It is easy to manipulate us because we are human, not fact-checking, emotionless computers. Wars start because, just like on the playground, you hurt (kill) my friends and I am now going to hurt (kill) you back. That's what the power and information brokers have been pushing to the people for as long as human societies have existed. We just have really, really, sophisticated ways of doing this now.
It isn't a bad guy vs good guy thing, it's a belief/faith thing. You have a faith that you may not even understand in your own society (Western). It is easy for you to believe what you are told by *your* leaders. Now, for a moment, why don't you try to believe everything said by some other authority -- say, the Chinese. Let's see how far you get. But, if *you* were Chinese, you would have an amazing faith in those leaders -- even if you did not like the Chinese form of government. Making Americans look evil is easy, if you are not American.
Keep thinking about it. Maybe you'll get there one day.