There will be some things you won’t agree with, but the core concepts of the theory are really hard to deny, and really help explain why certain parts of the game feel...dream-like and off at times. It’s also very much in line with what Nomura wanted to explore in Versus XIII and also mirrors a lot of what Nomura was interested in evoking with KH1.
I'm not too familiar with Nomura's original vision for Versus XIII - can someone fill me in?
Also, this may be far-fetched, but I tend to enjoy reading Kingdom Hearts through a mythological/psycho-theological lens - my experience of playing through the last chapter of KH3 (everyone dies --> Final World --> Lich --> "re-birth" (through/by sleep?)) struck me as reminiscent in some ways to the journey the soul takes in the moments following death as described in the
Tibetan Book of the Dead. Note the following quote from the hyperlinked summary: "The Bardo Thodol teaches that once awareness is freed from the body, it creates its own reality as one would experience in a dream."
Not everything that happens in the KH3 sequence has a direct analogue, but in brief: Sora "dies"/has a near-death experience. His soul travels to the Final World, which is positioned as the threshold between sleep/dream and death. Chirithy, in effect, offers him the choice of either passing on (to the "Clear Light of Ultimate Reality", aka true death) or painstakingly gathering (remembering, holding onto) the pieces of his heart (his
personality, who he
is, which is held together by memory -- and, as we know, memory is indeed the "key" or "glue" to existing as a unique personality in the world of Kingdom Hearts, as we see with the return of Roxas and Xion, respectively. Also, it's Sora's remembrance of Kairi and the others in the Final World which tethers him to the world of the living, as it were). At this point Sora begins, metaphorically speaking, descending (or perhaps the better word is "diving") down through the various stages of the Bardos, in the Book of the Dead's terminology, desperately clinging to life, to his sense of self, to those he loves and the memories which he cherishes (diving through worlds to save his friends, as he chases the Lich) - that is, further and further AWAY from the "Clear Light of Ultimate Reality" (Kingdom Hearts, anyone???). I found YMX's dialogue here to be particularly noteworthy: "Dream by dream, you nearly buried yourself in the dark of sleep. And now you're at it again? The Lich you've been fighting... It exists to usher hearts down to the depths of darkness. If you chase it, you will condemn your heart to that same abyss." A couple things worth noting here: The Lich strikes me as similar in nature to the "Lord of Death" described in the Book of the Dead, who appears all the way at the bottom/end of the near/post-death "dream" (the Third Bardo): "a fearsome demonic deity who appears in smoke and fire [...] The soul who is still not liberated [...] will now be drawn remorselessly toward rebirth." Of course, the degree to which we take rebirth/reincarnation here literally is open to interpretation - but the parallels are fascinating. Tempted deeper and deeper into a dream, further and further away from the Light, into the darkest abyss. Only to be - reborn! Into a... dream world? Another worldline? I'm impossibly curious to see what direction Nomura ultimately decides to go with this, but in any case it's chock-filled with symbolic and metaphysical meaning. I'm of the belief that there's a strong tie here to the "price to pay" for abusing the Power of Waking - Sora's disappearance and all that. Others have also speculated that the MoM disappeared for similar reasons. I also do quite like the idea posited by Ballad of Caius above:
When Kingdom Hearts was plunged into Darkness, it went to sleep and the events we are experiencing are the dreams of Kingdom Hearts itself. The MoM is a scientist trying to escape from this dream.
Similar idea, just applied more generally - to the world as a whole/Kingdom Hearts itself. Perhaps the "price to pay" is being lost in a labyrinth of dreams, unable to distinguish true reality. In fact, YMX does say: "If you chase it [the Lich], you will condemn your heart to that same abyss." Um, he DID chase it. 6 times.
In any case, this is of course all speculation and a highly subjective reading, but suffice it to say that the experience of the last several hours of KH3 were, for me, incredibly dream-like and seemed to defy all logic while simultaneously being propelled by some kind of mysterious, alternate logic. When I encountered the Sleeping Realm Theory several days later it really resonated with the experience I had with the game, and heightened my suspicions that this series is beginning to dabble with some profoundly metaphysical concepts.
Real trippy shit. Gonna stop typing now.