Many are stuck on a "good and just" America and can't even admit the other logical possibilities that aren't so happy and innocent. The same people that plead "logic" and "sanity" are the very people won't don't understand that logic is about working through *all* existing possibilities methodically. Discounting possibilities without being able to disprove them is the true insanity. We don't teach critical thinking skills in schools because... we can't think critically.

The title of your post is rather ironic as the one thing nobody could learn from it is logic. There are an infinite number of possible explanations, including an infinite number of theories in which the whole world is a dream in my mind. So I could not methodically work my way through all of the possible explanations. And as you are not running down the infinite list I can see that you don't take your own idea seriously. So let's move on to how we really can learn about the world. We can learn by proposing explanations and subjecting them to criticism. Sometimes we can even exclude a whole category of explanations because they are all susceptible to arguments of a particular form. I exclude all explanations that involve the external world not being a dream in my head without running through all of them by using a philosophical argument against solipsism, which may be found in The Fabric of Reality, by David Deutsch. Basically the world I see around me is complicated and autonomous from me so all solipsism really does is relabel the external world as a dream. Similarly I exclude all conspiracy theoretic arguments by arguments which may be found here.