The American Revolution
I was know-it-all precious child (with a Genius level I.Q.) that loved nothing more than memorizing facts, and regurgitating them to the amazement and annoyance of adults around me. Eidetic memory was one of my gifts, so like most kids, repetition and showing off was a pastime.
In 5th grade, I was doing my usual routine; I'd been assigned American History, specifically the American Revolution. So later that day, sitting around the dinner table, I was telling my parents all about it. How the Patriotic Americans fought insurmountable odds and injustice, and took on the largest empire in the world (the British empire), and defeated them. This was peppered with names, dates, and other trivia to drive the point home (I could recall anything in the text book).
My new step-Dad (born and raised in the U.K.), had probably had about enough of the know-it-all 10 year old (with a 10-year old's black-and-white view of history and life), so he said, "that's interesting, but it's not the History I learned growing up".
I thought, "what do you mean? History is facts and figures. There's no such thing as different Histories". But he plowed on.
He explained how in the U.K. he was taught about how a bunch of fanatics, zealots and kooks (independent types) who couldn't get along in "civilized" European society left or were driven out to start new lives in the Colonies. These Colonies were heavily subsidized by the British crown (managing shipping, infrastructure, government, defense, and so on)... and for that, they paid taxes that would be the envy of us today (a small fraction of our current taxes). But still, those rabble-rousers were unhappy, and started a petty insurrection.
Of course the mightiest empire in the world at that time could come in and crush them if they wanted. But this was one small colony among many all over the globe. And a funny thing happened... the French and later the Dutch used the revolution as a reason to get involved, attack the British fleet/shipping, and were surprisingly successful. Now shipping and control of the seas was very important to the British empire -- so they focused on that (and not the colonies). After years of the American Revolution being an excuse, the British weren't very upset to let the annoying colonies go, especially if it means removing that excuse from the French/Dutch -- so they "let" us go free.
Now that was quite a different view than I had learned.
And I went to the REAL library (not the school one), and looked up real books (not lame Elementary school History books) with the intent of coming back and proving him wrong. But a funny thing happened; his view was as valid (or as invalid) as the version of history I was taught.
There were multiple views of history, and it was much deeper (and more interesting) than what was taught in school. The more I looked at the levels of humanity and motivation by the different founding fathers, or the British, the more interesting it was. You really had to understand many sides, and many motivations to understand what happened?
I quickly learned to distrust the dogma I was being force-fed by public education. Those bastards had lied to me! And the seeds of critical thinking (skepticism) were sowed, by the distrust of my teachers. All because I accidentally got a diversity of views, that public school had suppressed.