There is good reason to question what you “know” for sure—because everything you think you know may not necessarily be so. Here are ten good reasons why this is so, or isn’t so, depending upon how far you want to take the idea.

    From what we presently know scientifically, these things are as factual as gravity; but then again, the true nature of gravity seems to be under some scrutiny from certain possibilities proposed by the last Voyager I and II deep space probes. What is permanent, scared and absolute? You will probably be inclined to reject the relevance of these ten things, but if that occurs, you will at least know why.

1. The brain’s operational capacity is way beyond your ability to think about it and all that it does and can do. We invented computers from the human brain model and yet computers can “out-think” us by galaxies. They can create separate realities we don’t have the ability to anticipate and can analyze problems at levels we can’t even access. The smaller version of this is that we can have certain ideas, but those ideas themselves have enormous consequences apart from us thinking them.
   
2. On top of this problem, most thinking is unconscious and to take our dismal thinking potential from the present10% to even 50% strength, requires us to think about our thinking and most of us can’t slow down long enough to begin to do that. Maybe this explains the Bible’s wisdom of settling for innocent, childlike faith and understanding of incomprehensible things. Of course you can either do that in the beginning or come back full circle to that starting point after all your side, zigzag trips. Either way, you oddly arrive at the very same reality—you run short of knowing something for sure.
   
3. Because of this brain-thinking mismatch, the brain reduces complex, interactive, circular realities down into artificially simple, causal, linear ones that are easier to comprehend and manage. The brain has mercy on us because it knows we would go completely insane if it unleashed all the infinite realities that are going on simultaneously to flood our limited, puny consciousness. It would be like trying to hold the Pacific Ocean in a spoon or eat a hundred million square foot buildings in one bite.
   
4. Everyone is familiar with optical illusions. If your visual perceptual process can fool you into seeing something that really isn’t there, so can your thinking.  That is not a far reach at all, it is just a crawl. This may be where time and space merge into movement. It’s all a blur so you can’t really see anything anyway, despite what your eyes convince you is there.
   
5. It is extremely difficult to step outside the particular viewpoint you are looking at things from, but it is this particular viewpoint that determines most, if not all, of what you see and “know” to be true . When you stand in the middle of the country in a horizontal field, the planet appears to be relatively flat; but go on a trip to outer-space and then take a look. That kind of paradigm change is what opened world trade and literally changed the face of time.
   
6. We can easily form very strong beliefs about the absolute truth of something with minimal proof (Santa Clause, The Easter Bunny), and this quick belief becomes almost impervious to disbelieving despite compelling evidence and disproof to the contrary. If we can’t argue the rationality of something, we blindly accept it on an intuitive feeling or faith; and the more we focus on these untruths, the stronger they become, e.g. a smoking habit that defies the possibility of lung cancer.
   
7. We also have a very clear preference for believing in the truth of concrete, tangible things we can verify with our senses personally, as opposed to believing in something that is abstract and secondhand even with overwhelming evidence it its favor. Some single, personal, firsthand experiences of an emotional nature can easily become universal fiats that can start wars.
   
8. We get to know something best by taking it apart and studying the differences; but when we forget to put it back together and notice the similarities of the two halves, we only have half the picture as our only viewpoint. And then, whichever half we are studying becomes our only reality because we can’t see the flipside at the same time—when we are busy living and studying life, it is kind of hard to see and understand the truth of death. When we are experiencing discomfort, we are unable to see any comforting light at the end of the tunnel. Sometimes our wacho thinking imagines that light to be a freight train.
   
9. We think and communicate with words that are only slim and dim approximations and wimpy weak representations of the real things they stand for, that are often way beyond our comprehension and understanding. Think about the problems we encounter when we use simple words like love, true , good and right, to express very complex things that may take a lifetime to begin to scratch the surface of understanding. We can never truly capture the true and complete essence of these things with a language that divides a thing further from our understanding.  That is probably why there is non-verbal communication—to get the information directly to our brains without the truth distorting interferences. But then, we even think we can interpret non-verbal communication verbally. Ha to that!
   
10. To seal our mental casket, we rely on our unreliable memory. The indisputable fact that most people resist, however, is that the brain’s memory process distorts information with all these above brain tricks, and so you really can’t rely on absolute truths that you think you remember.

So, what can you do about all this mess? First realize that it is highly likely that over half of what you think you know for sure may not actually be so. Then you can catch yourself with your hand in the cookie jar, allowing your brain to play all these tricks on your thinking, and gradually become more critical of what you accept as true and gradually replacing untruths with more complete and correct truths. Take a well deserved bow if you can jack up your thinking IQ by 10%.