riginal SDMB thread - Why does schizophrenia manifest itself in such predictable ways?
If your thinking is largely in step with that of the rest of the world surrounding you*, you do not experience disorientation and the sense of conflict that you would if the rest of the world held to several shared opinions and ways of looking at things that made no sense to you and you could not understand why they didn't see the world as you did.
What you don't realize, if "reality" for you is pretty much the same as "reality" for other people, is how dependent we are on the confirmation of other people's observations. It is reassuring to be able to do the many different variants of "Did you see that?" and get a quick little reality-check from your neighbor. We do it all the time.
I say "we" guardedly. I was diagnosed schizophrenic. I don't see the world as most people do, and have found it frustrating all my life that others don't see the world as I do.
One weird way that this conflict has of manifesting itself is that the voices of people (can be a specific person like your Dad, or, more often, a kind of composite, like an informal archetype rolled out of all the teachers and other authority figures you've ever known who could shame you and berate you and make you feel like you had done something wrong or unforgiveably silly), parroting back the kind of non-reinforcing messages that you do get from your neighbors and whatnot, can start talking to you as if an actual person were right there speaking inside your head. These voices are almost always, exclusively, chewing your butt out, yelling at you, explaining how you are wrong wrong wrong and often also culpably blameworthy for how you've affected other people in the process of being wrong.
owlofcreamcheese is therefore pretty damn close, except that there is a value judgment inherent there which I do not make. (I am a radical schizzy and don't think that the contents of the worldview that constitutes "sanity" is an accurate reflection of reality, except that it does predict the behavior of other people fairly effectively as a result of being shared).
Oh, and the other problem with being conceptuallly isolated like that is that you don't have anyone to say the variations of "Did you see that?" to (because no one is on the same channel as you), so you are deprived of the reality check that you have ceased to be able to rely on. That means that if you (the weirdly thinking person) and your neighbor (a conventionally minded person) each have a peculiar morning on which you reach an invalid conclusion that seems real to you at the time, your neighbor is more likely by far to get grounded on it the first time he or she talks to someone and discovers that they don't draw that same conclusion. You, on the other hand, can much more easily step out into weirdsville. Notice that I'm drawing a distinction between thinking thoughts that are not shared by other people, including thoughts which contradict those which are, but which are essentially valid, and thoughts that are not shared by other people because you've (at least temporarily) lost it and accepted as valid something that ain't, and don't realize it yet.
If you're gonna function as a schizophrenic at large, i.e., as a person whose thought systems are largely incomprehensible to the world and who rejects and/or completely does not understand the thought systems shared by the culture around you, you aren't gonna make it without a hell of a lot of resiliency and a sense of humor about the times that you do cease to make sense, which is going to happen, which is a real arrogance-piercer and in-your-place-putter although it doesn't invalidate the rest of your head's contents when it does.