I think about it in terms of photography (since I'm presently obsessed with my new camera!~~)
The act of OBSERVING ... causes a change in behavior? Could very well be true but I've also noticed that a very rapid shutter speed in bright light conditions will give you a "stop-motion" picture which ... looks quite different from anything we ever see with our eyes in the "real" world.
We get expressions on faces of people that are simply hilarious ... half asleep ... drunk looking ... outrageous "emotions" that aren't really there at all.
We can see birds with their wings in an extremely clumsy position that would seem to indicate instant plummeting ... and yet in "real" life, they take off and fly with ease of professionalism.
We look at the sky and see that it's blue but we are ALWAYS surrounded by the same-but-denser atmosphere and so ... we should see blue all around us, shouldn't we? What's strange is that a camera PICTURE will show us that blue -the greater the distance, the more blue there is- but/so why don't we "see" it with our naked eyes but see it in a picture? (You can "clean up" many long distance photos if you reduce blue and cyan color saturation .. and then it looks more "normal.")
The one that really got me though and shouldn't, because the explanation is quite obvious when one thinks about, is .... perspective.
Now, when an artist draws a scene in two dimensions, he simply makes further-away objects look smaller. A straight train track for instance, is shown as two "parallel" lines that get smaller and come together in "the distance. That looks universally right to pretty well everyone because that's how we all see "it" in real life.
So if an artist is standing in front of a general store in an old western comic, he shows a straight street in front of himself, going laterally to each side, with the buildings getting smaller to each side and the street getting narrower to each side ... and that looks right to us. That's how we think we would see the fictional scene if we were standing in his shoes.
A camera, however .... DOESN'T see it that way!
The closer a camera is ... to the scene it's snapping directly in front of itself ... the worse the "distortion" becomes ... where a truly "straight" line ... becomes the curve of a circle instead.
If you want a camera to take in a very wide view in one single snap, you use a wide-angle lens and/or a "fish-eye" lens. When you look at the PICTURE it produces though, the view is not flat but curved like a ball. Tall buildings will lean away from each other in all directions so that the image looks quite surreal and unnatural.
If you stand in one spot and carefully hold the camera level and snap a number of photos while turning a bit each time before snapping the next ... you can create a "panorama" of those pictures by joining them together later ... so that you get a single picture showing a fairly large spread of scenery. But alas ... unlike the artist's depiction ... the scene will appear to be a convex circle!~ And of course -physically it would and should ... but why did that catch me by surprise when I first experimented with making panoramas? The artist's rendition looks right and the camera's rendition looks wrong but universally, we would all agree on the artist being more right than the camera when that's completely wrong.
Here are 3 examples
showing the effect. (Click on the image to enlarge it if you want).
So if a person never considers any other viewpoint than the one he has ... and if he never "moves" the slightest bit from his own position ... the "world" will always look absolutely solid and unchangeable to him ... "proving" that everyone else is wrong and he is right ... because from HIS perspective, nothing ever DOES change!~~