Looking further into the dream

I am currently writing an outfilled entry to my dream journal on the pc. I dreamt of a cabin, and I only saw it from the outside. But I started wondering that if I saw any of the interior in the cabin. Then my mind went into this cabin, and there it was. It fit perfectly in the cabin, even though I didn't see it in the dream, an outline of the interior is there. and I feel I didn't make it up just now, I feel like it was there before.

Any thoughts on this? is the interior from the dream or is it from my imagination right now?

anyone have input on this?
I just did the same thing with another dream. It's like the location is already planted there.

I don't know about your specific case, but I often find that I know things about locations in my dreams that I haven't actually seen in the dream. My mind makes it up while I'm in the dream.

The same happens for thoughts of other people, reasons for things that happened which I would have had no way of knowing if the dream was real life. So I often find myself writing things like "[The person] might have been trying to lure me into the alleyway, but I'm not sure." I've wondered if all the 'maybes' are bs. My subconscious knows the intentions of my DCs, and they don't have intentions apart from what I get a sense of.

So it happens often to me with location. You probably had a general sense of what the interior of the cabin looked like. But I don't know, maybe you came up with it when you woke up.

I'm not sure, it's like it was there from before, because the things visible were only the things visible from the windows. And when I make stuff up I kind of decide what goes there and there, now I can't change it, it's kind of stuck.