The difference between the world of what is real and the world of the unknown is like the difference between walking down a path with intermittant lamps along its length, and walking through a cave with only a single lantern at your side.

On the lit path, you may always see what is directly ahead, and directly behind. You cannot expect your vision to be of an infinite span, but you may be lucky enough to see anchoring landmarks. You know how far away that notably shaped tree is, or how long it'd be back to that one roofed structure given your current position. When we walk this path, we are allowed to build on what we have directly observed on our way up the rungs of the ladder. Every step is built on the last.

In the cave, you may never build on what you have seen. Your world is simply the small aura of flickering light directly around yourself, and with every step you take, your world is redefined. The only thing that can truly be known to be real is that which is directly observable. This world as it stands might as well cease to exist the very moment you leave it, even with only a few steps forward. There is only here, and here is subject to change.

Picture an existence where your entire world was all the space illuminated by a single, valiant lantern sitting on a table. It has never moved, you have never moved it, nor have you even considered ever moving it. This is how it is, in your mind. As sure as the sun hangs above the earth. You are content in this world, and you eat, and you sleep, and you embrace this lanternlight-sized cosmos.

Now, imagine: Despite your complete lack of consideration of the lantern, and your complete lack of desire to move it anyways, one day it simply falls over for no immediately apparent reason. It becomes clear that you have been presented irrefutable proof that the borders of your world are not immutable. For the first time, you consider the idea that the confines of your reality can shift to the previously non-existent.

How long could one realistically be expected to not take up the lantern? Can you remain where you've always remained, now with the knowledge that there is a "behind" your bed, now that "darkness" will never again be synonymous with "wall"?