I am continually struck by the profound lack of understanding we tend to exhibit toward an entire spectrum of experience. That spectrum is of course the hidden nature of "non-existence." We might pass the entire idea off as being childish or impractical, but the fact remains that half of the world is simply "not there" and yet it affects us, all the same. We are constantly touched by an unseen presence of a "non-real" and yet valid portion of the universe, a portion that is physically contained within other universes and bleeds through into our own. Imagine that you are flying through the Omniverse with a special kind of perspective, (Physicist, Dr. Fred Alan Wolf would undoubtedly invoke his famous Dr. Quantum's "quantum goggles" if he were writing this blog.) This perspective allows you to see the omniverse as an infinite sea of mirror-like bubbles. Each time you peer into a bubble, you see that universe. If however you simply observe the bubble from any distance without peering inside, it reflects all the other bubbles around it in a blinding display of light. To the inhabitants of each bubble-universe, its limited reality is the only one that is considered to be "real." After all, reality is always a local concept! So you peer into bubbles all day long until you are sick and tired of looking. What do you suppose you would think about the things that you saw? Well, for one thing, you would have done something quite dangerous (without knowing it) you would have infected yourself with the foreign logic of other realities. This infection or is a difficult one to treat, if one really wanted to treat it anyway. The difficulty here is that you can't effectively unlearn something, especially something so important and so vital to the life process, it becomes hard-wired in after so long. The more "foreign" the logic*, the longer the exposure and the more profound the impact of that experience upon the observer, the greater the reduction in the observer's mind's ability to function (at least to a valuable degree) in their own universe. The end result of too much exposure is inevitable, insanity. It should be noted that the observer would not clearly understand the effects until the changes had already been made.
* It is important to understand that the term "foreign," as I have used above, is intended to describe the degree to which the (newly) observed universe's initial conditions deviate from those of the observer's universe of origin. Any other effects that have occurred due to chance (or since the formation of the observed universe) should not and will not affect the observer's reality concept or their ability to function within any given universe. It would affect the observer's specific experience with that universe. Imagine a world where planet Earth was ruled by telepathic spiders, alterations in evolution of a worldline from that of our own worldline's history should significantly change one's viewing experience.