(this may take a bit to explain, so bear with me)...
Actually, that's only the half of it. There's a reason why you are inside a hologram, and there's a motive for making it that the ego wants to keep a secret.
The purpose of the physical universe, as a hologram (a holographic dream), is to profoundly obscure awareness of God. The ego has used it to create a way of experiencing which seems to be completely devoid of God. The physical universe was made to literally shut God out and to make it look like He does not exist. And it's done a pretty good job, because we all believe it. And you don't even realize you believe it.
As Jesus says in ACIM: "Nothing so blinding as perception of form".
So, how does this work and how does it obscure God, and why is form (physical matter) blinding? And what's this got to do with holograms?
Ok so bear with me as I try to explain, this is VERY hard to explain because it defies a lot of ego logic, so let me know if I lose you.
First we define what God is like.
God is oneness. God is omnipresent, meaning He exists everywhere. And God is whole and completely equal everywhere. What this means is, if you could think of God as occupying 'space', no matter where you are in that space, God is *exactly* the same there as He is in any other part of it. Over here He is God, over there He is God. No matter where you are in God, it's exactly the same as everywhere else.
It's kind of like if you were to take a road trip inside God you'd be driving for a while and then remark to yourself, you know what, this place looks exactly the same as the place we just came from. Exactly. Then you drive some more and it still looks exactly the same. It's almost like you aren't going anywhere. Ok so God is the same everywhere.
Now there's another part to this. This may be hard to imagine, but ALL of God is in all *parts* of God. (NB: The ego will say this is IMPOSSIBLE!) As you think of God as occupying space, and you're driving in that car to different parts of God, and its all the same, you might still be tempted to believe each 'part' or 'location' in God is actually a DIFFERENT part, but just 'looks' the same. Like, as if the whole landscape is a giant set in a movie and its all painted in white paint. You're accustomed to thinking that the stuff 'over there' is not the same as the stuff 'over here', in some way. Its sort of similar with God.
ALL of the properties of God are everywhere. ALL of the awareness of God is everywhere. ALL of the attention of God is everywhere. So then when you ask yourself, what parts of God are 'here', in this location, the answer is, ALL of Him. And when you then ask yourself, well what parts are over there in that other part, the answer is also - ALL of Him. And what about those parts you were driving through 50 hours ago... ALL of Him was there.
To the ego this would have to mean, well, if all of God is here, then there's no other parts left to be elsewhere, so elsewhere there is no God. But in God's reality, in God's 'universe', somehow God is capable of being fully present in every single part of it at the same time. In this sense its almost as if God is PERSONAL, personal and local to every single part of existence, and yet, simultaneously personal to ALL parts at the same time. (Revelations speak of this intensely personal quality.)
You could kind of think of God as though there are trillions of copies of Himself, which the ego mind might be able to grasp. Except that in God there are no separations. Absolutely all of God's being, all of God's mind, all of God's identity, all of God's wholeness, is SHARED by all parts of existence. And when you try to think of this in terms of what you are USED TO, in the physical world, you can only relate to like a large stretch of land that you call 'The United States', within which there are many different distinct places. But if this land were God, everywhere would be the same and there would only be ONE of anything. Hard to get your mind around!
Now, this is where the ego comes up with a device to shut God out.
As we know, the ego's only tool is "separation". What the ego does, is it tries to take the omnipresent oneness of God and start to make it `look like` God maybe ISN'T the same everywhere, or ISN'T fully present everywhere. The only way it can obscure God, i.e. make it seem like God has gone away, or that God does not exist at all, is to go against the nature of God. So if the nature of God is, all of Him is the same everywhere, the ego's attack will entail the idea that only PART of Him is PARTIALLY present in each location. And this implies that God is riddled with contradictory differences. (The ego is contradictory, God isn't).
So now it's kind of like, you're driving in that car through God and you notice that, some of these hills are starting to take on a different shade of color. There's some slight differences in how things look over here than how they looked back there. At first, the separation isn't strong or well defined. In fact it starts out very subtly with just a 'hint' of differences. Then as you keep driving the intensity of the separation increases, and it really starts to stand out that different parts of God are different in quite noticeable ways.
What's happening at the same time is that the ego is now suggesting, by manipulating your perception, that maybe God is not fully present here. Maybe God has some parts of Himself which are sort of 'tied up' elsewhere, or occupied or busy with something else, so he can only be partially present. And also the ego is suggesting God isn't the same everywhere. The way God is over here is not quite the same as over there, and the over-there parts are somehow distracted from being fully present here.
This is how the holographic dream is born. A hologram is the concept that "the all is in every part" - which is pretty close to the way I described God being if God were a 'space'. i.e. All of God is fully in every part of existence. If you want a primer on holograms or whatever maybe check out The Holographic Universe which is quite an interesting book.
Anyway. Basically, at the early stages of the hologram forming, a lot is still shared and things are still almost-one. But the 'density', if you will, of the hologram, increases by continued ego belief in separation. The ego starts noticing and emphasizing the ways in which different parts of existence seem not to be the same. And as this grows stronger, it starts to seem more and more as though only a small part of God is still present here, because all the `other parts of God` are apparently quite different and have become quite finite and specific, and they're all localized to other parts of existence. So what exists over there maybe does not or cannot exist over here.
As this progresses, in the mind, the hologram 'solidifies' more and more. Or another way to describe it is that, formless reality in which everything is the same everywhere starts to 'descend' into localized properties, differences, separations, divisions, fragmented identities. The more separate and clearly defined these differences become, the more the awareness of God's omnipresence, God's total attention, God's total awareness, and God's equal presence everywhere, APPEARS to be shut out of awareness. If it seems true to you that differences are real, and that you start to look AT those differences and breathe reality into them, then you will become fixated on the ways in which God is NOT THE SAME ANYWHERE.
Not only is God not the same anywhere, but this also has a dire conclusion. If you really strongly believe in the reality of differences, you must start to fixate only on the appearance of what's left. All of the different 'forms' of difference. And those forms of difference is what we call PHYSICAL MATTER. The solidification of wholeness into locality, the contraction and density of 'energy' if you will, is what happens in the 'lower levels' of the hologram. The further into separation and differences you go the more 'solid' everything starts to look, and the less there is any evidence or awareness that God is present, even AT ALL. At a certain point you would be forgiven for even believing that God does not exist AT ALL because ALL you can see are the intense, real-seeming differences of physical matter. The physical universe 'stops' God from being able to be in all places at once, or in all places equally, or in all places fully, replaced with the idea that everything is separate from everything else.
So while holograms start out subtle, or what scientists call 'diffused', the lower levels of the holographic 'dream' are much more divided and separated out and form 'images'. When you see the little images on your credit card which look 3d when you see them from different angles - those are a form of holograms. You see an image, and yet when you look from another angle, you see another image. Its as if ALL of the images are somehow 'in' the one location, SHARED. But on the level of physical matter, you can only ever see ONE of the versions of the image at a time. You can't see the 'all'. You can't see all of the angles of the little dove or whatever it is in the hologram, because it is obscured by the rules of the physical universe.
So when the Course is saying, nothing so blinding as perception of form, what it's saying is, physical matter is a very dense level of a holographic interpretation of God, which has the effect of completely obscuring any trace of oneness or all-ness, so that you fixate on only one version of one image, in which it seems like NOTHING is shared and therefore there is no God. 'Sharing' is the same as 'Oneness' so if there is no sharing (co-existing in the same space) then God doesn't exist.
In the physical world, an object does not seem to have anything shared with another object. There is no sense of there being any unity between them. There is nothing 'the same' that is exactly the same in both. This defies the property of God that all of him is everywhere. And then because the stuff that is `in` one object is NOT the stuff that is `in` another object, defies the property of God that all of his same properties are in all objects at the same time. So if you look at that matter and you BELIEVE the illusion that it is trying to SHOW you, its statement of 'what is', you will be blinded from seeing God.
Physical matter LITERALLY was made by the ego to make the properties of God totally obscured and distracted away from. If you believe physical matter does not share anything, you do not have awareness of God. It blinds you. If you do not believe that physical matter contains all of something which is also fully present in other parts of matter, you are blinded to God. Matter, in all its forms, is a giant blanket of the 'undoing' of God's reality, God's omnipresence. It is a physicalization of the idea of separation, but even moreso, the idea that God's law-defying everywhereness is NOT what existence is like, and therefore God does not exist.
It is designed SPECIFICALLY to shut out the awareness of God's presence so that, IF your mind is aligned with it and IF your mind functions according to the 'laws of matter' then you WILL NOT SEE GOD. If you SEE MATTER, you do not see God. Not fully. If you do not see PAST matter, you do not see God. If you fixate ON or look AT matter, you will not see God. Your mind needs to become able to OVERLOOK (forgive) the ILLUSIONS that are presented to you BY MATTER ITSELF.
This isn't just a matter of fixing your mind and staying in the world and not seeing God. Your mind needs to go back `up` the hologram to the point of Oneness, eventually, so that your awareness is able to discern that a) God is fully present, b) All of God is here, c) All of God is everywhere, and d) All of God is the same everywhere. If you believe that MATTER IS REAL or MATTER IS TRUE, then you cannot be aware of God. If the form of matter dictates how your mind perceives or you believe in its ILLUSION, you cannot see God. Matter is BLINDING. That is its function. And it will never have another function until it is undone.
What the ego in your mind does, is it looks at matter and uses it as a 'model' for what is true about your mind and what is true in your perception. Its illusion infuses into your mind and you take it at its word and consider it 'reality'. You buy into its illusion, its way of obscuring God, and its statements of the ways in which God is not here, God is not everywhere, God is not ALL in ALL. That is matter's message. That is the 'state of existence' of the physical universe, designed solely to shut God out - IF you believe it is real.
This also leads to another way to say, the physical universe is just a holographic dream, and it is just an illusion designed to obscure God, and NEVER will it be Heaven (because heaven is formless), and THE WORLD IS NOT REAL. Matter is not real. Separate forms are not real. Bodies are not real. Planets are not real. Physical matter is AN ILLUSION AND NOTHING ELSE. It is the illusion that God is dead and can never be real.
These are all ways of expressing the idea that God is not God, and that can never be true. And this is why eventually the physical universe WILL DISAPPEAR. Check out Gary Renard's book, or read this section of the Course "How will the world end": http://courseinmiracles.com/
I have no idea if I explained this well or conveyed what I wanted to. I had a profound experience a few years ago which SHOWED me an EXPERIENCE of this - I experienced what it was like to go up the hologram in my mind, back toward Oneness, and how this allowed me to be AWARE of God's presence - all of His presence in every part of the dream, and how this totally defied what 'form' was trying to telling me was the truth of existence. So I speak from experience, but these things really defy the ego's logic so it's very hard to put into words. Let me know if I need to clarify something.
All is not as it seems in this world. The physical world ITSELF IS the 'form' of the egos attack on God, and IS its defense. You think you only have defenses in your mind inside your body. But the physical universe as a whole is a giant defense mechanism - IN the larger mind of the Son of God. You're literally looking at the MIND of the Son of God attempting to shut God out. That's what this world is.