This post represents my speculation on the spirit and how it operates independent of a body based on my intuition and understanding of how our reality works.  I do get a lot of information about how the spirit operates from my dreams in my sleep.  I believe that ones spirit does often leave the body in ones sleep.  That we can gain a lot of insight from our dreams about how the spirit operates.  Spiritual training I believe also helps an awful lot to help one to better connect with the spirit world(that is located in the same time and space as the physical world and constantly interacts with it) and understand what is happening there while one is dreaming.

The spirit after leaving its body at death has to find the type of body that it has experience in operating. It has certain genetic requirements necessary to meet its needs. Some spirits are more specialized than others and have to have bodies that meet more specialized genetic requirements. Spirits can not escape the time and space they exist in. They do exist in a time and space when incarnated in a body, and when they leave their body must travel from the point they leave the body through space in order to get to another location. The spirit is less limited in some ways when it is without the weight of a body and can travel a lot more quickly and readily through space. But, it still takes time for the spirit to travel through space even when the spirit is not burdened with the weight of being connected to a physical body.. It is hard for a spirit(even without body) to travel through areas of space it is not familiar with.