My theory on death comes from self induced NDEs, it's part conjecture and part what I've experienced going thru these near death experiences. I won't go into how I do it save to say I control my breathing and allow my heart to stop trusting my body's autonomic functions to revive me.
First and foremost, the fear of death is the biggest scam ever perpetrated on mankind. The reason is we're already dead, the problem is we don't realize what death actually is. Death is a separation from your Self. Self is the 7 octillion atoms you contain within you, billions of which are thinking, feeling, sentient beings just like you. The proof is in the fact you don't even know they exist. They are your tribe, your own people who know you better than you know yourself, who support you in every single endeavor you've ever attempted without fail. You are surrounded by them all the time whether you know it or not.
The objective world is our individual world which is really a set of filters which tune out 90% of the subjective world we actually live in. Without it, there would be no way to create our individuality, without individuality there is no way to create companionship, friends, or society. The problem arises in thinking it is the only world we live in. Absolutely no regard is given to what occurs in our sleep and daydreams. If you pay attention to them, you'll soon see that everything in our waking reality is predicated on those dreams.
The dream world is a subjective reality. In the objective world you see an external world around you,with you at the center. In the subjective world you see the world within you, with you as the space that contains it. In the objective world everything is not you, in the subjective world everything is you. In this world you can look down and see your own feet, see your own hands, see what you look like to outside observers. This is impossible in the subjective world, because there is no point "outside" of you from which to view from. What you can see that is completely missing from our objective world is meaning. In the subjective world you know what everything means, which is the main reason you cannot and will never figure anything out by looking soley at our objective world. Looking for meaning in the objective world is a wild goose chase, an exercise in spinning your wheels and going nowhere. There is no meaning in the objective world. What things look like and what they really are have been separated into two different worlds diametrically opposed in their perspective.
Normally and what is supposed to happen is your own people waiting to receive you back into the fold. It is a birth like any other, with loved ones eagerly expecting your arrival and gathered about for the event. What actually happens is greatly complicated by those practicing sorcery and necromancy. You could say it's a bit of grave robbing with people other than your own attempting to intercept you before your own people get there. The human soul is the most valuable commodity in the universe and there appears to be some marketing and trading going on. This means you could end up with your own people, or you could end up with people who intend to enslave you. The latter could be anything from parasitic tribes hoping to profit off the work of others, to elite families practicing necromancy for personal gain, to the military industrial complex for insertion into metaphysical technology.
In going thru hundreds of self induced NDEs, I have experienced all of this to one degree or another and have no real opinion on the good or bad of any of it. At worst it's a pain in the butt sometimes when you're trying to connect with your people, at best anything your individual consciousness enters is a learning experience. You cannot trap a human soul beyond the point which it wants to be trapped... period.
I've found it's best to look at what we're going thru as a work in progress, with life and death as part of the same work. All of it makes for a system composed of individuals who consider your own individuality or soul as the most precious thing in creation, and that system will protect your soul above all else. The rest is just up to our own individual sense of adventure.
Probably not what you were expecting to hear 
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Circumstance Rules!