A freshly deceased mind, spasming out fragments of memories, mish mashes of whatever connections your neurons built during life. As you rot and the connections dry out and crumble away, the dreams have less architecture to pull from, and you lose the inclusion of memories of lesser importance. You have flashes of work, family, porn, memes, playing games, injuries, mantras, songs. Little micro-dreams of the school dance, that one ball game... and they occur less and less vividly, less frequently, based on how often you experienced them, how thick your neurons built the pathway. As it melts away you're left with images of immediate family, Bing Crosby singing Christmas carols, your church sanctuary....

This hypothesis has been heard and duly considered by NDE researchers and the sources I listed show it to be a much weaker explanation. In particular, a supermajority of NDEs report greatly heightened ability to sense and to choose, many NDEs, from people blind from birth, report experiences of vision in ways that cannot be explained ordinarily, and many NDEs report observation of contemporaneous events on earth that they could not have known without the NDE. Further, the NDE generally returns to a fully intact mind, not one that has melted away in any sense. So this explanation, while it might handle an isolated, low-detail case, does not account for the data accumulated by researchers in the last 40+ years of collation on the subject.