dreams are some unorganized data created by our mind. During the dream we are not seeing or hearing or touching anything.
Its just a collection of data and feelings that generated from analysis of the real data we collected during the waking time of that day.
We have no input, instead we are combining and remaking inputs we got in day.
The dream stores with visuals and sounds in waking time when we recall them.
And because our conciseness can’t understand some collection of data and feelings, it will convert them into the closest and nearest concept of that data.
For example we have a colored image and we want to print it, but our printer is only black and white.
So the printer would convert yellow to bright gray instead. Because it’s the closest and nearest color to yellow.
The colored image is our dream, printer is our conciseness ( our waking me) and the black and white image is what we recall from our dream.
Instead the printer is so much better than our mind.
For example we had data and feelings of shame and nervousness in our dream but when we recall it in waking life that data will translate into school and having no pants.
And the funny thing is it’s temporarily, it won’t store in permanent memory.
So when we recall that dream again another time, our mind have two sources for that dream.
The colored original image and the black and white, except that this time colored is fade and incomplete and the black and white one is less vivid than last time. So for better understanding our conciseness have to translate and generate a new image from combination of that two.
So second time we recall that dream it may change a bit or sometimes it will change a lot.
And still because our mind ia not sure about its translation, it will restore the second recall in memory with a tag of “I’m not sure if i translated this correctly”.
Some days later or even month we go in a office that look like the school that our mind translated for the first recall.
And because it’s similar, brain will pick that old memory with that tag and re-translate it with the new data collected from office and will remove the tag.
And we will wonder in that moment and we feel we were here before in a dream so we recall that dream again and it will regenerate again with this fact that it was office not school.
So everything would change to fit in office situation.
For example teacher would change into boss, etc.
People call this feeling “dejavu”.
Now with knowledge of this fact, imagine how complicated is lucid dream, our conciseness is awake during the dream and it’s constantly translating, and because we are still thinking ( thoughts are new inputs during the dream and we said in dream there is no input anymore, thats what put lucid dream aside from a normal dream ) our thoughts will instantly translate into visuals, sounds, feelings, etc.
by training your brain to restore memories of dream in permanent memory , you get less Deja vu that normal people .
simply put a dream journal beside your bed and write down your dreams as soon as you wake up.
and read them every day.
but why should we do this ? because we know that a lazy untrained brain is full of false dream memories , dreams we never had. we master lucid dream but we can’t remember our dreams so what is the point ?
Make your printer colored, 256 bit , RGB , HD, … with just a dream journal.
ive often had deja vu. sometimes i have memories of a house on a steep hill, i strongly remember living there even though I never have.
And after staying up with no sleep for 5 days I had a strong sense of deja vu. it is psychic. I am a very psychic person despite having autism and ASPD. I think dreams are more than just our brains reliving things, God gives us dreams and we can dream psychically and our dreams can instruct us on how to live our lives.
then how are we lucid dreaming if the source of dream is god? i dont agree on that.
in 3 main religion , they say deja vu is because we already saw everything before we born. but god made us forget everything or angle of oblivion, but sometimes we remember a glimpse of it thats what cause dejavu , which with all due respect is totally bullshit.
God is the source of some of our dreams. not all of them. 
Everything is happening all at once, our perception is what creates the illusion of separation. Time is cyclical in our physical reality, but beyond the physical it is boundless. Deja vu takes a certain presence, full awareness of the now and in the now. Maybe it tells us we are on track in a certain vibration, or perhaps it is a convergence of timelines, a moment that always happens beyond the assorted variables of the entirety of our possible experiences. For me, it is one of the most enjoyable strange phenomena of observational consciousness in the physical.
“I could see the past, present, and future all at the same time.” ~Nikola Tesla