That's really weird that you post this.
It seems that now that I've read this, I'm recalling feeling the exact same way during these hours... (when I'm usually still awake)
I find that during these last few hours I have more motivation and attention than any other part of the day. This is normally when I do all my cleaning, drawing, reading, writing...
It's strange because another part of that post, the fear/terror/paranoia, sometimes makes me jump from my chair for no apparent reason...
I think it's because - since there is almost no sound or hardly any movement at these times - that the slightest shadows, movement, or sounds just freak me out a little bit.
I would love to see if anyone else has thoughts on this... like an explanation I suppose..
I would assume it has something to do with our circadian rhythm or something like that being so used to sleeping at that time, that we're actually consciously experiencing a heightened awareness that usually takes places while we're sleeping.
just a thought