Sweet Unconsciousness

I don't know how you could learn to become properly unconscious, but if I were you, I would consider learning to lucid dream extremely high value.

When you say you had a real hangover, had you been drinking? If so, stop drinking.

Have you experimented with sleep posture? A cursory search turned up a 2000 study showing that sleeping in a supine position might contribute to lucid dreams. Some of the subjects suffered from hypnopompic sleep paralysis:

Dahmen N; Kasten M. REM-associated hallucinations and sleep paralysis are dependent on body posture. Journal Of Neurology, 2001 May; Vol. 248 (5), pp. 423-4

How do people not remember their dreams?

Well, by having our long-term memory bits not engaged in remembering the dreams, I'd guess.

Found this via wikipedia: http://www.ncbi.nlm.nih.gov/pubmed/21570

I suppose if you really want to experience something similar, you might try the magic of chemistry.

I'm curious about this as well, though I have what seems like almost the opposite problem.

I almost never dream at all, or if I do, the memory fades so fast that even immediately upon waking I am unaware of it. I don't just mean that I forget what my dreams were about, I mean there's no sense of having dreamed at all most nights. I dream perhaps three or four times per month, and remember things from perhaps one in three of those. I've actually been haphazardly training myself in Lucid Dreaming, and of those dreams I remember, I attain Lucidity more often than not.

I've always thought this was a bit strange, since I was able to become moderately accomplished at Lucid Dreaming, but utterly failed to retain memories of dreams much more often than before I started, and training yourself to remember afterwards is supposed to be easier than training yourself to attain Lucidity. What did happen, is I started remembering that I'd dreamed even if I couldn't recall any details or impressions about the dream. It made me wonder if maybe I was dreaming with normal regularity and the memories were just even further out of reach, or if it had actually revealed the full extent of how often I dreamed which was only a few times a month.

Either way it seems like something strange is going on, but if it's the former, then whatever's going on with me is an extreme example of people not remembering their dreams that may be relevant.

I find that I remember my dreams much more clearly when I wake up gradually and naturally. I generally do not remember my dreams when I wake up due to an alarm. This is only a personal empirical observation, so YMMV.

That first paragraph makes me sad I can't do the same. I have a HUGE number of mental anomalies, which has given ME many insights about how brains work that other people lack and probably would so for others as well if they could be communicated, and I strongly suspect some are even related to introspection in ways which allow greater access to both themselves and others and normal processes.

Sadly however any data would be noisy to the point of uselessness fr several reasons, including not having any model of what normal human functioning is supposed to be like and the language only supporting comparisons not descriptions and I wouldn't even know what parts where relevant anyway, and the fact that trying to introspective for an extended period of time or to deep tends to make my mind break down entirely and I start sprouting nonsense uncorrelated to reality.

The last person who told me that he sometimes remained conscious for the entire night, he subsequently developed narcolepsy. I don't think that clinical narcolepsy is a natural category, but a better one is having little or no sleep other than REM. In some people this eventually causes "excessive daytime sleepiness" and is diagnosed as narcolepsy. But most people with almost all REM sleep forget their dreams normally. If you do go directly into REM, you may find short naps very effective.

You might get some insight from this dream work writeup I posted on my blog from earlier this year: Dream Works.

It is not long and there are a couple of points that directly relate to your query.