NOTE: I honestly didn't set out to write this much, and it's a bit of a wall of text. Sorry. Feel free to skip unless you're genuinely interested in this topic and want to know what I have to say. "TLDR" might be very GD but isn't much to do with the topic at hand. I happen to have a great personal interest in this topic, so naturally have a lot to talk about. I've barely scraped the surface here so please forgive any slight non-sequitur or seemingly contradictory statements. I've tried to give as shallow an over-view as possible.
Anyone else had such a epiphany, or have any thoughts on the afterlife, or do you simply not believe there is anything more.
Someone once said "I don't have a
belief in God, I have an
acceptance of god [deliberate lower case]". That's pretty much my take on things, the 'afterlife' included. I think you're actually very much along the right lines when you refer to it being more of a natural phenomena than a supernatural event.
I don't particularly wish to go into great detail on here, but I've experienced enough to formulate my own beliefs through my life events so far. My current understanding (which is always open to change and 'evolution') is that we are - for want of a better word - multidimensional beings. By that I mean that the physical body and mind (which is a product of interaction between the body and the physical world) are separate to the deeper-seated and more permanent 'spirit' or 'soul'.
I would classify the 'gross' consciousness as something existing as an interface between this physical body and the world around us, and this is the thing that dies at the time of physical death. I do believe, however, that each entity/person/soul/whatever has a permanent (but not fixed) spirit, or soul, which from our perspective 'survives' death.
I use a lot of quotes and slashes because I think essentially at the moment mankind as a whole looks at things rather two-dimensionally and from a very limited perspective. It's like asking a frog born into a well what the ocean looks like... As such using mere words and hypothesising on a forum can never really get at the crux of the matter.
My main platform is that mankind has, unfortunately, greatly confused what you could call 'true spirituality' with religion. They are not the same thing, and in my opinion religion can actually interfere with the former; though not always of course. Being less religious and more spiritual never does any harm, in fact personally I would say I have no religion, but I definitely strive to be a spiritual person.
I don't really like elaborating on forums, but essentially my views in a nutshell are along the following lines:
* We each (spiritually not physically) stem from the same Source. You can call it universal consciousness, the cosmos, 'God', the Great Spirit, dharmakaya, whatever. It's pretty much the type of thing Jung used to talk about. This is where the misconception arose about "God created Man in his own image". In his SPIRITUAL image, not his physical one. God is not a man, or an individual, and he doesn't sit around in a place called Heaven. God is a living, all-pervading thing manifested in each one of us as that spark of life often called Mind, Soul, Spirit etc. God is also love, light and all things associated with goodness. We are essentially all kin to each other, all a part of 'God' and you could say (superficially) that we are all thoughts in the mind of 'God'. God is not a physical being, has no 'physical' existence and as such is more a concept than a person.
* We are spirits having a human experience, not humans who have spiritual experiences. People take 'spirits' and the like to be some supernatural sci-fi airy-fairy nonsense, but in fact I would assert that quite on the contrary it is not only natural, but a fact of live we've come to overlook. Castiel talked about science leading us away from spirituality and I think to a degree that's correct. Not that there is anything wrong with science, quite the contrary, but rather in future I think that science will become more adept at measuring the things we currently refer to as 'supernatural'. As such a homogeneity will arise between science and 'religion' (spirituality) as we come to see them as sides of a coin and two ways of looking at things.
* The physical world we see and experience with our conscious mind is a creation of our own ultimate mind. From our limited human perspective it appears that the world happens to us, and that we just experience it (or suffer it) as if we were corks floating about an ocean. However, I would assert that in fact the world is a concept, or creation of, our own consciousness and that, to coin a phrase, "that which is thought, or mentally imagined, is manifested as physical actuality". Unfortunately it doesn't work on a very gross level (you can't imagine yourself a Euromillions win!) but it's essentially true. This physical experience is ultimately illusory, transitory and very much dream-like. The appearance of an independent 'self' or 'I' is illusory. Quantum theories now abound on this very issue.
* During physical life, our experience becomes very single-pointed (limited) and we tend to see ourselves as individuals, amongst a sea of other individuals, with a short finite lifespan. Conversely, I believe that we are all manifestations of the same source, nobody is truly individual except at the very grossest level, and that we exist in several 'dimensions' simultaneously. I see our physical mind as a TV set, receiving our consciousness (soul/spirit) from a separate dimension/multiverse. Amalgamating this with the 'interface' between the body its external environment creates an illusion of 'self' which is in fact the grosser physical 'mind' that dies at physical death. The true personality experienced internally to each physical being exists independently and continues (with all memory and experiences intact) after physical death of the individual body/unit.
* Meditation, prayer, introspection and so on are all useful tools. None is particularly superior to another but all provide valuable 'grounding' to our spiritual self and the 'source' (godhead, God, Buddha-nature, dharmakaya, cosmic consciousness). Losing touch with our spiritual side doesn't necessarily provide very evident 'symptoms' but by maintaining a spiritual 'life' as well as a physical one, we strengthen our experience, transform our minds and ultimately progress along the path and gain more valuable insight.
You can live a purely physical life, ignoring the spiritual, and that doesn't necessarily have to be a problem. We all grow at our own rate. I do believe in multiple lives, not necessarily in the reincarnation sense but that explanation will suffice. The only harm from denying our spiritual nature comes when we allow it to grow into malice, hatred and other such negative emotions. "Physical life is all there is, screw everyone I'm building gas chambers and I will rule the world for my own benefit!!1!". You don't need to be religious to be spiritual, and you don't even need to be spiritually aware to live a good life... however that can't alter the fact that you HAVE an ultimate spiritual nature, and eventually you will have to confront that fact and build upon it.
* There is no religion except service. Whilst religious ritual can be helpful in many ways, we shouldn't make it the primary focus - rather use it as the tool that it is. Confusing religion as the goal rather than the tool has caused untold harm and horror, and is contrary to all that is good. Provided we do 'good', serve others with no regard for self, and try to do no harm as we accumulate experience and progress ourselves spiritually, no more could be asked of you. Anything much beyond that is a mechanism of control dreamed up by 'religious' figures.
If there is no afterlife, no 'God', no so-called supernatural and no karma etc, why live a moral life? Why serve others? Why do 'good'? Surely it's better to be scientific and Darwinian to the end; fall out of your mother's womb, use her resources to fight your way to the top of the world and slay anybody who stands in your way? Is it only fear that there are others stronger than you that stops you descending into this kind of society? Are rules, law, justice and 'morality' all a shield to prevent the even stronger from slaying YOU? Or is it that we are inherently good, there is more to life than this physical 'dream' experience would suggest, and that our very basic tenet is service to others, the progression of our 'soul' and ultimate reunification with the godhead?
* The only heaven and hell exist in your own mind. I use mind here in the ultimate sense - the emotional, spiritual and immortal mind that never dies with the physical body. Once the physical self falls away, we find ourself existing in another dimension/plane/realm/whatever. Each dimension exists in the same space as the others, merely at a different vibration. The faster the vibration, the 'higher' and 'purer' the existence. Your own emotional state, your level of development and your actions will determine the nature of our "after death" existence. The more 'advanced' you are spiritually the higher the vibration of your "soul" and the higher and purer your plane (dimension) of existence.
There is no judge but yourself, and the "spirit world" or "afterlife" exists here and now congruent with our own physical world. We just can't usually experience, see or measure it. The best way to explain it, I think, is to imagine a pyramid that is dense and heavy at the bottom and progressively becomes lighter and more etheric towards the top. If you lived a very material life, can't conceive of the spiritual and so on, you'll migrate to a very earth-like existence after death and in many ways the 'new' existence or afterlife will be as solid as this one.
More experienced souls, or those who have progressed greatly in one life, will naturally be much less materialistic and will be able to conceive of (and be comfortable in) a much less material existence - or even a formless existence as part of a communal "spirit group". We are essentially sparks from the consciousness of that which we call 'God', experiencing the world(s) ultimately to return to our source and amalgamate our experiences into it. We will retain our ability to form independent thought and mind, but are essentially a cog in a much larger machine. The "spirit world" is just another dimension, as real as this one, and the people are just as alive and just as normal as you are. They just exist on a different vibration after 'physical death'
* Essentially, we are co-creators with God rather than his (its) subjects. We just tend to forget that while incarnate in this life. Such forgetting is inherent in the limitation of the physical form, as the physical mind simply can't process such things. This is where meditation and "reconnection" to our "higher self" come into play as it frees us from this single-pointed physical-only perspective, albeit temporarily.
I know that I haven't explained myself very well. An old Zen master once said you can't write an essay about how a banana tastes - you just have to shove it in the other guy's mouth... He was right.

Our experiences make us unique, but ultimately contribute to the whole. We all have our own path, and our own place on the ultimate path of progression, and it's not my place, nor yours or anyone else's, to 'convert', convince or try to push beliefs on another. Science is as valid a method as any, but we must remember that heart transplants would have been 'supernatural' 200 years ago, too...
No doubt most people reading this won't "get" what I'm saying at all. Fair play. I don't ask you to believe, heck I don't even care. As I said you have your own path and you can believe what you like. Just afford me the same courtesy. That's all I ask.
EDIT: I should also add that I think we are living a physical life for a reason. For that alone, it can be just as bad to spend too much time spiritually as too little. Or to put it another way, it's as dangerous to spend too much time with your head in the clouds, as it is to spend too much time with your head up your own arse. We have a physical life to lead, so don't spend it all meditating in a cave or with 24/7 lofty 'ideals' and 'mind states'. I just 'know' that you can't die for the life of you, and once you embrace the fact that you are actually an eternal being and part of a much larger picture, you tend to find that you can live this life with much less fear, much more enjoyment and much more gusto than before. It should be paradoxical, as you'd think that the belief you only have 'one go' would lead to this result. However, I tend to find the opposite.