I think the present moment is constructed from recycled memory.
I think you are correct.
As we have discussed before, we are a closed box/ system, our experience of reality is from within our own personal simulation driven/ fed by our external senses.
Our simulation of the world is created from many types of memory, when your external senses detect something you are not directly experiencing the stimulus, you are recalling similar facets from memory and recreating the current experience, this is also part of how your imagination functions, and optical illusions can function, etc.
I believe being asleep is exactly the same as being awake except the external senses are quiet, your internal simulation of reality is still running except now its not guided by sensory stimulus.
A slight nudge from the senses triggers a variety of pre-processed information.
During sleep the simulation doesn’t change, there is no ‘sleep mode’, your brain just keeps doing what it always does except now it’s left to it’s own devices, this is why you can still experience a narrative except it usually doesn’t make sense and can twist and jump between topics. When awake the brain ‘locks’ onto the current most salient sensory pattern and recalls memories accordingly, when asleep the brain will lock onto the most salient part of the current memory narrative, there is no stability provided by the external senses.
This is how external sounds can ‘creep’ into your dreams and influence them, your brain is just incorporating the sounds into its current simulation model (dream) and this effects the narrative, and indeed this is how hypnopaedia works.
The so called ‘stages of sleep’ are produced by the lack of external sensory stimulus. Your brain is constantly trying to house keep even when you are awake but the activity levels are too high so it gets behind, the functions are suppressed by high activity.
Flushing neurotransmitters for example, they build up in areas of high activity to promote/ target neurogenesis and synaptic growth. As soon as your brain falls quiet the process is able to come to the fore and catch up, this causes the first stage of sleep. As they are cleared beyond a threshold normal functionality begins to return, your simulation starts to run as normal, you start to dream. Your brain is running the simulation back up to speed ready for you waking up.
This is one of the reasons why going without sleep is mentally debilitating, your memory recall starts to suffer, you start to hallucinate, etc, and eventually you die lol.
I use all these principles in my AGI model, it requires regular sleep cycles and cannot function or even learn without sleep.
