Whenever I have a lucid dream using the WILD method why do I always end up in the RTZ?

I don't lucid dream that often and I'm one of those unlucky people that have to work at it to get results but when I do I always find myself in the RTZ, normally in my bedroom either stuck to the ceiling or the side of my bed and it takes lots of energy to get myself moving which normally leads to me coming around to full waking consciousness. The times I have been able to stay fully lucid long enough I've managed to take a good look around and everything is exactly as it is normally i.e. my room is identical with the bed, mirror, desk, wardrobe, etc, etc. all in the same place and looking the same. The only difference is the dullness of it all, but saying though, it is always night time so it makes sense for it to be dark.

Anyway, I'm just wondering, why do I always end up in the RTZ and not some other higher plane?

I always tell myself to remember the next time I go lucid to shout out a place name such as the Moon, but I never seem to remember as I'm always too excited just to be lucid

What's your thoughts on this?