Just one thing my mind came across a few days ago, it's goes into the "How do I know anything is for real" direction.
I was thinking about some ethic lessons I once had and that our teacher wanted to show us how to build a legit argument and proof of something. He made a negative example, those were his words: "You see, just because everyone believes something to be true, it doesn't necessarily have to be true (agreed, but now it comes:). For example, back in the days, everyone believed the world to be flat. Now we know it's not."
Back then I was, oh yeah sure.
And the first part of what he said is absolutely true, but the rest?! Everyone believed the world to be flat? How the heck does he know? And how the heck does he know that it's not flat now?! Like... I don't know. I don't know! Maybe the earth is a octahedron, no idea.
But what struck me was: I never ever questioned it. How could I not question this? Why don't we all question everything all the time?