If one grasps the five dimensional model, boundaries, and one's relative position within that model of consciousness, one has a fundamental understanding of consciousness. I did say it was deceptively simple, and more than once.

The modern day analog is computer systems.

From memory, the people who designed UNIX (a computer operating system) set out to make the equivalent of the human mind. (Those who know better can feel free to correct me : ) That aside, the standalone computer workstation can be said to be an individual human. Workstations are a part of a local network. Local networks are connected within a larger network, and so on.

If we understand computer networking, we can understand networking within consciousness.  We should keep in mind that some networks are not connected with any other networks. This is so in conscious too. Additionally, navigating computer networks isn't as easy as it seems.  Boundaries in consciousness also act as firewalls, as they do in networking.  We all have our own firewall, which is of course our boundary of self.

Understanding the fundamentals of consciousness allows us to understand some of the mysteries, and not just how a fairy uses the surface of a pond to visit our world.

"World", now that reminds me of an important point. The word "world" has a special implication that applies here. We have heard such terms as the world of martial arts. Also the world of embroidery, pottery and so on. We can also say the world of the Catholic, the world of Islam, and so forth.  I have heard it said that the church is not the building, the church is something that accompanies the Christian.

That is how closed spaces in consciousness works.

Dreaming is the ability to create closed spaces in consciousness, thus dreams, and what are dreams if they are not worlds.