Sleep as Rebirth
When one goes to sleep one wakes up refreshed, having gone through (hopefully) at least one REM cycle. this is for a variety of reasons, mostly to do with memory. Everyone must sleep, and while science has found plenty of ways it affects us, mostly the lack of it, it has not found out the true nature of dreams, or the exact extent to which it is necessary. People theorize (going back to the Greek gods Thanatos and Hypnos) that sleep and death are linked, either literally with the more wild interpretations that Sleep is Death. That we die every time we sleep and are replaced with someone with all our memories, or more abstractly with the notion of Sleep as Void. That the natural state of “us” without a body is sleep, that we sleep before we are born and after we die. I believe both of these are false, though the latter is more plausible, but I'm not going to get into that today. What I’m here to talk about is the continuity of the self and the idea of Sleep as Rebirth.
I’m going to be getting into a few complex philosophical concepts so here's a quick overview. The self (at least in my definition) is “you”, or in other words, what drives your consciousness, the force that allows you to perceive yourself and understand your own thoughts. What do I mean by that? Well, you know how when you dream you can potentially perceive yourself but can’t really act like you would normally (barring lucid dreams of course)? Well that's because I believe dreams either discard the self entirely (for the moment), or simply don’t engage with it. You are able to take actions from a surface level, but not think through them in the way a lucid person would. I do not know (or rather, do not have the time to expand on here) whether it's because the self needs to recharge from all the decision making and general living you’re doing while not sleeping or because it's partaking in some other activity. What I do know is that the vast majority of the time, the “self” is for some period of time, not active during sleep. This gives way to the idea that Sleep is Death for some people, that this gap in continuity means that you are not the one experiencing anything in previous days, and the (typically horrifying, but sometimes comforting) conclusion that you are replaced by someone else every day. I’m more interested in this idea of a continuity gap, a gap in what you are conscious of, a gap in what you can truly call “you”.
While I believe Sleep as Death is untrue (there simply isn’t enough going in its favor), we can pull ideas from it to form Sleep as Rebirth. Regardless of what you think about it, sleep does sort of reset you, often times it brings you back to the “default” of who and what you are, flushing away all the built up, loud thoughts that can occupy your head, (most of the time) resetting your mood back to a stable one, and sometimes giving fresh insight on problems not able to be dealt with the previous day. Of course, there are limits and it only does this at the start of the day, making way for your normal processes and routines to influence you in the same or a similar way each time, but it still is useful. This leads us to the idea that Sleep as a Reset can be taken further. One of the major functions of sleep is to take short term memory from the day and load it into long term memory, which has different methods of recall, and of course to induce dreams, which science has yet to completely crack. Since I believe the self is not present, I believe dreams are primarily ways to 1 test itself in real world scenarios, and 2 take the short term memory and make use of it while it is being committed to long term memory (perhaps the dream is literally part of the process), and engage the other parts of the brain while the self is away.
Anyways, at the end the self returns and is greeted with a slightly different long term memory and potentially memories of events that didn’t really happen. Of course the self is resilient and doesn’t reject these new circumstances, but since it is so tied to these, it is changed slightly as well, without being present in the slightest. This is the core of the theory of Sleep as Rebirth. Sleep resets cognitive buildup, commits short term memory to long term memory, and creates dreams for some reason, which go to memory, all these and the fact that our memory is imperfect, and that old and irrelevant memories fade causes us to change over time, maybe not very much, but there is a change that happens while we sleep, the old us might not be dead, but reborn anew, slightly refreshed, slightly different.