Reincarnation is in my opinion an overly simplified concept, designed to be easily understood and accepted by the general population. But the theory of reincarnation falls down sharply when closely examined. That is, if you understand how standard linear time sense behaves in higher dimensional levels, i.e., time sense fluctuates. As far as it goes, the theory of reincarnation is clear enough to explain some very complex esoteric matters in a simple way; without giving people headaches whenever they think about it. It also allows for the illusion of the continuation of present consciousness, unchanged and progressive, with only an occasional memory loss to mar its course; marking the division between each Reincarnation.
This makes it easy for people to accept the bones of the incarnation process. It gives them the benefit of a rational afterlife belief-system containing the simplified essence of the whole truth. This allows a measure of independence and security, and a reassurance of the continuance of self, i.e., life after death and reincarnation = a kind of immortality theory that people can easily accept and relate to.
But the whole truth of reincarnation is so extraordinarily complex it is not so easily grasped.
At the top of the dimensional structure is ONE consciousness. A SINGLE mind (call it universal consciousness, The Great White Spirit, the mind of God: pick one?). Or split it into three if you like: Father, Son & Holy Spirit, or many more if you prefer the demigod perspective, i.e., Hindu beliefs, etc. However you conceive this structure, at the top of it all rests a single consciousness: the original spark of consciousness that created and is continually creating the entire multi-dimensional universe we call home. But grasping and relating to the ONE is not an easy thing to do. The ONE is so far above our understanding of what consciousness is, it becomes incomprehensible to the human mind: except of course in the abstract; which is the only realistic way this can be perceived and related to.
The most popular way of relating to the ONE is through abstract simile, i.e., God is like the father of all fathers, or, God is like the mother of all mothers, et cetera.
Beneath the ONE are layers of consciousness (relating to subtle dimensional levels, i.e., the astral dimension, mental dimension, etc) where the ONE fragments and splits into multiple parts, with each lower layer splitting again and again into many more layers and parts, and so on, until you get to the physical dimension, the dimension of Maya, the dimension of solid illusion where we as energy-cum-physical beings can experience the limitations of the physical universe through our physical bodies. This, in a way, makes us human beings the myriad eyes, ears and consciousness' (in the physical dimension) of the ONE great universal mind above us.
At the very top of the dimensional spectrum, at dimension ONE, there is NO time. Mystically, this is understood and experienced as The Eternal NOW. This means there is NO TIME. There, time does not exist and everything, the past, present and future, are happening all at once in the eternal NOW. Every layer beneath this takes on a little more time sense (steadily increasing in time sense) until we get back down to the physical dimension; to our Real-Time dimension of solid illusion (our normal physical universe) where time becomes relatively linear once again.
To support this: whenever you experience higher dimensions, say during OBE, you will always notice a significant variability in time; in your sense of time passing during each experience. Modern physicists are already working mathematically in several different dimensions above but related (or linked) to the physical universe. The great physicist Einstein stated that at some point in the dimensional spectrum there must be a point where time does not exist, where past, present and future coexist simultaneously.
I have traveled to and experienced higher dimensional levels where there is NO concept of time at all. But the sensation and perception of time passing is also quite variable in the physical universe, and time sense is entirely relative to your state of mind. Look at how time flies when you are happy, say when you are spending time with someone you love. But oh how it drags and drags like a heavy stone while you are bored, or while you are waiting or experiencing something you dislike.
In a way this can be likened to a simple pyramid structure:
@ = The Eternal Now
OOO = The physical dimension (Real-Time, here and now)
The above diagram shows the ascending and descending layers of the ONE consciousness, splitting into more and more parts as it descends into the real time universe (the here and now).