I follow "The God of Infinite Complexity", which means reality is actually infinite complex beyond anyone's ponder and fathom. The meanings included in our thoughts and talking, the way we think and talk, would be considered too simple and maybe stupid in the long future.
So based on my humble faith, I would like to say the explanation to nde, and the truth behind this phenomenon could have three kinds of possibilities:
First possibility, so many documented nde cases suggest and lead to such possibility that human mind and the thingy which is often refered to as "self" or "ego", could rely on something other than organic brain, instead of macroscopic brain organ, thus could kick away brain organ and exist without it. The "thingy" which our conceptual terms "mind", "self" or "ego" rely on, is something microscopic so even macroscopic brain organ dies, they still exist invisibly from our eyes, in a manner of subatomic, quantum or superstring scale, or in some hyper dimensions which current Science hasn't touched onto.
Second possibility, ndes are produced by brain, and if all the peculiar cases are veridical rather than bogus, their outstanding traits really only indicate the possibility that brain itself has some nouveau and gorgeous functions or potentially such latency, nothing needs to be produced by something other than brain, brain itself truely can have such capability which current Science still has not even a bit of grasp to understand.
Third, the third possibility to explain all of these, is that both the two possibilities mentioned previously are wrong, instead, a more advanced statement or many more advanced statements should be invented to explain all of these, but for them I'm completely unable to fathom or talk a single bit about, the effective explanations which are truely capable of grasping the truth, are beyond our current thoughts or language, every attempt to address an effective explanation is futile.

I have no right to step forward an opinion about which possibility is conclusively correct or tends to be correct, because first I myself never had any nde, not even any hallucination or lucid dreams, second I have no close contact with any nders or researchers in this area, everything I know about this domain is from online reading.

But from all of I have read, I want to share my thoughts about nde and to see the others' response to my thoughts, I think there had been no evidence really sufficient to even lead towards the first possibility mentioned previously, the core and crux of this thought is the key word: DETAILS!

NDEers used to say their experiences are "definitely real", "hyper real", but reality contains infinite details, so many nde accounts have little details. For example, accounts of seeing deceased relatives during ndes confuse me a lot, because almost every cases narrating the meet of deceased relatives only include several repetitive speakings, mostly are "It's not your time yet, go back for your mundane tasks." But different people should have different personalities, should concern different things regarding and between themselves and the subject of ndes. Consider a pair of parents meet their beloved son long after his attending a foreign university for 4 years and has come back hometown in mother country, what should they talk about, something before their long time depart, during this son's foreign life, and right on the way back home, there are a lot of details to share, they shouldn't just talk about: "It's not your time, you still have tasks on earth to finish."

Someone would argue that nders don't necessarily narrate their experiences in great details especially regarding their personal or private conversations, or the ndes often last very shortly so there is no time to show someone's personality in the short communicating, but with so many cases which had shown unrealistically simple scenarios and similarly lack of details, I incline to think maybe these are cheap imaginations produced by brain, most people are incapable of forging a long, fresh and complex story within a short period, this is more like a brain's mechanism, rather than a reality of another world.

Similar problem exists among nde accounts about visiting an unknown place usually full of light but nothing more, being granted "knowledge of everything" which is nothing more than a single literal phrase recursive of itself not even more complex than a simplest math formula or a segment of java code used to query a database record, and reincarnation accounts which claim they were pilots during World War II in their last lives and simply show their savvy of a single fighter plane terminology, these could be easily forged by brain without need to resort to some form of otherworldly forces.

But bearing my previous concerns in mind, how do we interpret the accounts of ndes being described as "hyper real", "highly organized", "splendidly vivid", and etcetera? I think an analogy might be possibly used to erase the contradict or paradox. Consider our physical world as a real photo, and nde as a photo being heavily processed by photoshop, a real photo can be dull, but it's real while a photo being processed by a graphic technology which is unimaginable one hundred years ago, can then become cartoon sharp and more attractive, but it's unreal and distorted.

"Hyper real", "splendidly vivid" are only feelings, and feelings could be produced by brain, while infinite details can't, and the latter forms the reality.

I am a Chinese, sorry for my English, I should stress I don't mean anything conclusively or with certainty, I should remind myself always to be open-minded and truely skeptic without biasing on any unsolved mysteries, I highly respect Science and science is progressing rather than concluded, I just put a little curiosity on an obvious fact about nde accounts' lack of details in many aspects and I would be grateful for anyone's response to my thoughts, thanks!