Can someone explain to me what the Subconscious is?

I was just watching Spongebob, and it the episode where he has to erase all is memory except for knowing how to cook and cater for Squidwards fake restaurant.

Anyways theres a scene where in his brain theres a metephor where a bunch of small Spongebobs in an office with a a stash of drawers full of paper and they start trashing everything.

My question is, is the subconscious a data bank of all previous memories and experiences of a person?

Can you dig into previous memories which you consciously forget in a lucid dream?

The subconscious in all it's glory is a very opaque and not well understood.... concept?
We have theories but not much concrete evidence of anything.
We cannot really put our heads around consciousness. "The conscious conundrum."
I am firm believer in the subconscious regardless of what facts are present at which are not.
I also believe that you are mingling with your subconscious in a lucid dream.

There is so much to learn. We are only scratching the surface. But that is the exhilarating part. So much to learn and experience.
MY dreams never cease to amaze me. My subconscious is ALWAYS putting a new face on and old canvas.

haha you watch spongebob

Hm i would view it like this, but i'm a bit weird like that.

Your entire consciousness, from being just a tiny bit conscious about something, to being fully focused on something, is the world. There is nothing for You outside of Your entire range of consciousness at any given moment.

Only a tiny bit of this world we are very conscious of, to the extend that we know we are perceiving that bit. What we call consciousness.
We can let that part go, it isn't subconscious.

Then there is a part, a very big part, we would say we don't know about. It's the part we are so less conscious of, that we choose to call it unconscious.
Now that's not subconscious either.

What's left over is the part of the world, or information, that we know about, but aren't very conscious of, to the extend that we aren't aware we are perceiving it. Of course we are aware to some extend, but so little we don't call it aware any longer.

That part of the world is what i call the subconscious.