"Your focus determines your reality"
-Qui-Gon Jinn

I don't know why, but that line caught my attention when I first heard it, and it stuck with me.

Now, there's a lot of schools of thought/religions that suppose that dreams, visions, hallucinations, and near death experiences are all planes of perception, and they're perceptions of other realities.
Maybe even THIS reality is a dream of another world, and there IS no reality, so your mind puts you wherever your soul needs to be like a level in a video game.
Well, that's the general layman's gist of it.

Now, we know GL is inspired by a lot of eastern religions right?

My theory, is the focus/reality thing is a clue to force dissapearance.

Notice Obi-Wan goes into meditation before he vanishes, and Yoda knows he was dying, so he probably did the same.

I think a Jedi who does this uses the force to achieve a moment of ultimate clarity, realizes "life is but a dream", and "focuses", into a higher reality.

This is why their body goes with them, and the body going was the biggest clue.
Where would the body go scientificly?
By the laws of science, there should be ashes, or a big nuclear explosion from vaporized atoms, or something.
Matter can either change state, or become energy, but it can't just vanish.
But, that's science, and that's our little made up rules of our imagined universe.
The only other place for the body to go, would be another dimension.
Or, since reality is an illusion, there really is no flesh, no atoms, no relativity etc, therefore Obi-Wan's presence is just poofed away like a forgotten daydream.
He just lets it all go.

This can also explain the nitpick of Obi-Wan and Yoda looking how they did in death, but Anakin is all healed.
Your focus determines your reality.
Obi/Yoda/Ani appear as how they picture themselves.
Obi and Yoda where comfortable as who they were, they identified with those bodies, so they appear as how they were.
Anakin obviously wouldn't want to be Vader anymore, so he appears as how he imagines himself now that he's good.

Why not make himself Jake Lloyd or Hayden Christenson?
Hey, maybe he's just honest with himself.
Obi-Wan and Yoda aren't superficial about themselves, why should he be?
Or, maybe he passed into a reality where he wasn't borg-ified, and that's really how he looks now.

Maybe, since we're dealing in higher dimensions, perhaps good ghost Anakin, and Darth Vader are 2 distinct but conjoined 3-dimensional facets of a 4-dimensional being, like 2-dimensional planes along a 3-dimensional cube. Maybe we're all 3-dimensional extensions of our higher self into this world. If so, Anakin is only bunged up, and Vader-ized on one side of his dice. When he turns good, he shifts to the next non-Vadered Anakin side of his dice. Maybe this is the TRUE meaning of TURNING to the dark SIDE.

So, when Anakin passes on into the force, he spins over to how he'd have looked if he didn't get all injured, back to his good side, to his ideal self. His focus determined his reality. Once one passes into the next plane, it should be as easy to access one's whole hyper-self as it would be to move your arm. A small matter of focus apon reality.

Now of course, the Jedi have to die to dissapear, but if there is no reality, there is no death, so they just slip into the next plane.
But, once they do this, they're no longer a "playing character", they're more like a "Dungeon Master".

If the force surrounds all things, and (based on my previous Jedi future prediction theory ) surrounds all time, so too does it apparently surround all dimension.
But, maybe in higher dimensions, the full shape of the force is something that we can't understand with our limited minds.
Maybe what the SW characters consider as "the force", is just the protrusion of this higher thing into our dimension.
After all, they don't really know what IT is! The very term "the force", shows that it's their vague little label for it, so they can at least call it something.

So, If reality is an endless loop of dreams within dreams, and there is no reality, and these dreamed dimensions are connected through the force, and the force has it's own reality, then the one true reality is the force.

And since the force is the real reality, this would indeed be the highest level for a Jedi to achieve!

*Takes a bow*