Welcome as the matrix
Thomas A. Anderson is a programmer at a software development company and has an illegal part-time side gig under the hacker alias Neo. Neo is contacted by a group of "rebels" led by Morpheus. The latter reveals to Neo that the world he lives in is a "make-believe" world that they name the Matrix. The Matrix is actually a computer simulation of the world as it was in 1999, created to control people. Morpheus gives Neo the choice to escape from the Matrix to the 'real world' and take a red pill, or take the blue pill and return ignorant and stay there. Neo chooses the 'real world' and wakes up inside a giant 'battery cage' for humans.
So much for the movie "The Matrix".
There are spiritual fantasies, at least, I call them fantasies, that assume there is a world 'behind' or in another 'dimension' that is more real and better than the ordinary world we normally live in. Through certain spiritual techniques you can then get acquainted with that other dimension and live your life from there. Or maybe you enter that other world after you leave your earthly body. Sometimes there would also be visitors from that other world or you would get messages from "beyond".
The idea of a better world waiting for us is a comforting thought for the sometimes miserable conditions of this 'earthly vale of tears'. But how can we know that such a thing exists?
Most people in this vale of tears assume that there is an "external" world and that, for example, the eyes are a kind of window through which we, residing behind our eyes, as it were, look at this external world. The world we experience consists of colors, shapes, sounds, smells, tastes, which are said to come from the 'external world' and furthermore all kinds of emotional impressions and thoughts, coming from the so-called 'internal world'.
But in fact that is not how I experience it if I am honest. There is, as far as I am concerned, only one, undivided experience. There is no partition between my thoughts and the computer screen that I am observing here. They are, of course, different things. But the experience is singular. I can give my attention to my thoughts and a moment later my attention goes back to the screen. I don't feel like I'm crossing any boundaries at that point. It is one fluid, flowing event.
The world as it appears before us is the only reality we know. The nature and origin of this fluid, flowing event, which we can call both mind and world, will forever remain hidden from us for the simple reason that an eye cannot see itself or a hammer cannot knock itself. You cannot step outside your perception and see how this actually works. We simply cannot know what a world outside our experience would look like, even if it exists or not.
Everyone experiences the world in their own way. As adults, we can inform each other of what is happening in our world, although I will never be sure if what is being said is actually true or is complete nonsense, because that communication also happens and is interpreted in my world.
I can also imagine that the world is experienced completely differently by a newborn than by an adult, while the baby and the adult must process the same sensory information when they both look at, what appears to the adult to be, for example, a red apple on a white background.
I remember some time ago teaching computer classes to people over 80. The desktop of a PC looked very different to them than it did to me. For example, I saw all kinds of 'icons'. They didn't. They saw no difference in all that color information on the screen. For them it was one flat, chaotic image, in which nothing could be distinguished. In the same way I imagine how a newborn child would see the world: without recognizable shapes, without a distinction between foreground and background. Apparently a learning process takes place, whereby gradually the world, as we adults see it, is formed.
So at a certain point a distinction is made and suddenly there is a difference between, for example, foreground and background or between areas with different colors, or between an 'inner world' and an 'outer world'. Again, I can imagine this to be similar to an object that suddenly jumps into view when viewing an 'autostereogram', which at first glance contains only chaos or a random pattern of dots:
So an external world, outside our experience, may not exist at all. In any case, we simply cannot know if it exists. And of course, if there is no external world, there is no internal one either!
You are not in the matrix. You are the matrix.
And there are only 'blue pills'. But there is more than enough to be discovered within our 'ordinary' reality, since we think 'ordinary' is just 'ordinary' and there is apparently a deep need to embellish, decorate, cover and explain away our naked existence...