It is an extraordinary to realize how rapidly a dream narrative proceeds compared with waking thought - so that a detailed dream experienced as lasting many hours, may turn-out to have happened while just a few minutes elapsed during waking life (by the clock).
In the past I have tried to 'explain' this by assuming that 'Time' operated differently in dream compared with waking. And also in dreamless sleep - which is the opposite of dreaming - because only 'an instant' in subjective experience, may have lasted several hours by-the-clock.
My 'Time' explanation was that time ran more slowly in dreaming than awake, so that more could be fitted-in; while the opposite was true for deep sleep.
But if Time cannot legitimately be abstracted from the living of Beings - as I argued recently - then be must explain this phenomenon differently.
The reason why I think that so much more can be experienced in dreams is that we are then (more-or-less) cut-off from 'external' sensory and perceptual stimuli, and from real interactions with other Beings, such as other people.
When we are interacting with 'externals' then our experience can proceed only at whatever speed these interactions occur - for example the timescale of a conversation or of physically moving through a landscape.
But in a dream, we are 'modelling' reality using material from our memories - and our processing (combinations, extrapolations and speculations upon) memories.
We could think of this in terms of recalled memories being the dream content; and what we do in processing these memories as the dream plot.
So that the primary process of dreaming can move as fast as memories are-being-recalled. This central nervous system process occurs with a timescale of less than a second, maybe tenths-of-a-second.
This is relatively much faster than interactions with the external world, so dream experience is relatively more concentrated.
What of our emotional responses? Emotions are 'enacted' by changes in body state - and these have a timescale of approximately seconds - for example, to feel terror the sympathetic nervous system needs to be activated (taking some seconds), and adrenaline is released into blood to circulate around the body (some tens of seconds).
Whatever the exact speeds, it is certain that emotions are enacted relatively more slowly than memories are recalled. But perhaps the emotions happen about as fast as we contrive our dream plots.
We would therefore expect that specific dream 'events' move faster than the body can enact emotional responses; and therefore that the emotions could easily get 'out-of-synch' with the dream contents.
But the overall dream plot might well be in accordance with our dream emotions, even when specific dream contents are not.
And this is, I think, a very common, indeed probably the usual experience of dreaming.
We often experience a kind of mismatch between dream events and emotions - and there is often a pervasive feeling of perplexity or confusion as events seem to be coming at us too fast to understand.
On the other hand, the overall shape (or plot) of a dream does tend to match up with the emotions - e.g. scary dreams have scary plots.
In dreaming I think we are therefore getting a kind of very concentrated experience that we ourselves concoct; and we react emotionally to these concoctions.
Dreams are therefore potential learning experiences, just as is waking life; and probably just as necessary and valuable.
But the source of dream experience is almost-wholly inner; and this accounts for the different subjective feeling of a dream, when compared with waking life.