Although your last statement is generally true, I don’t believe this would be quite possible without the proper training, or at least a few years worth of self-teaching.
People can train their minds to do anything, there are people with “talents” who have taught themselves how to calculate pi in their own heads to the 80th digit, people who have taught themselves to retain such massive amounts of data in their short term memory that they can relay a 100 digit number exactly how it was written when they only scanned each number in the sequence a single time. These people had proper training, whether they trained themselves to do it, or had professional help, but each of them had some time to perfect what they were doing. Unfortunately, in my opinion, and I will tell you most people here will share this as well, no “average” lucid dreamer would be able to go over the entire material in a textbook, then re-create the book from within a lucid dream, and be able to re-read all the material he just covered within that exact textbook to the exact words.
Sure, everything is stored in our subconscious, but there is a reason for that. What would happen if we retained everything we saw in a day, every feeling, every thought, every bit of knowledge scrounged from god-knows-where, where would that put us? Eventually, probably a catatonic state. There’s a reason there are 5 layers of physical consciousness, the stress of everyday life would kill most people if it weren’t for the second layer of consciousness, in which a person isn’t aware of most of their surroundings, and can easily block out most outside stimulus so that they can escape from the stress of things.
Take this for example: If you ever had to read a large amount of subject matter within a small amount of time, and needed to retain all of it, did you ever get a headache/migraine afterwards, or found your knowledge of what you just read a bit “fleeting”? I know I’ve been in a situation like that.
My fixation with the “SCP” series and the “monsters” listed in them has caused myself two migraines to date. I can’t help but to read all of these fictional stories of captured creatures, these places, and these beings all of which are so unique, each having a story in which some correlate with others, to the point to where it seems I “forget” certain ones, and my mind seems as if it’s on fire because of all the words being processed, and all that I’m having to remember to where it seems almost cumbersome to continue reading.
This is exactly what I’m talking about. Imagine if I was to retain every detail of what I just read, right when my mind started feeling as if it was burning. Imagine the pain I would be in, because that pain would be magnified by at least 5 times. To prevent this, your mind begins skimming through smaller details, and sometimes it slips into that second state of consciousness to where you’re not entirely sure what it was you just read, or you forget most, if not all of the minor details.
This is a protection mechanism. If we didn’t have this, people would be braindead before they even got done with the second grade. They would be braindead geniuses mind you, but braindead nonetheless.
If you were to go through the proper training, sure you would be able to recollect everything stored in your subconscious from some point in time, there are people who can do such things IRL, but I believe they have a quicker way of doing such a thing, and I’m pretty sure it’s called hypnotism.
