There is, I feel, an artificiality about the common Christian idea that this - my mortal life - is bounded in one direction only; that is in the past by conception, while eternally unbounded in the future.
I think this artificiality contributes to modern mainstream atheism.
On the other hand; I am sure that this is my first and only mortal life.
And, however things may have been before Jesus; I am pretty confident that the divine plan since Jesus is for as many as possible to make a permanent choice of where we go and what we do after this life: the permanent choice of salvation.
We are (as a general rule, probably with some exceptions) supposed to (i.e. God hopes that we will) choose resurrected eternal life in Heaven. That is the divinely-desired permanent choice.
Or...otherwise. And that 'otherwise' may not necessarily be permanent (although it can be - i.e. Hell) and 'otherwise' may in theory include the possibility of reincarnation.
Yet to desire reincarnation (and therefore to reject the opportunity of Heaven Now) may be rare in reality in these days. It may be (I suspect) that most of the people who say they want reincarnation are saying so for spiritually-bad reasons; and that reincarnation may be a superficial cover-story for some other motivation such as refusal to repent a particular sin (or sin-in-general); or a fear-motivated refusal to choose to align-oneself with God, creation and The Good.
i.e. For a modern Western person to say he desires reincarnation may in practice be another way of saying that he has rejected Heaven, and may well prefer Hell.
Yet; when I look back before conscious life, my assumption is that I (personally) was continuously experiencing, learning, participating throughout - as a spirit-being, not incarnated.
And I think it likely that it is memories of these personal experiences that may well lead to the phenomena which are usually interpreted as 'having experienced reincarnation'.
In other words; some of my time before incarnation was - I'm pretty sure - spent in types of involvement with particular times and places of human history. Therefore it is quite natural for me (and others) to be very interested and concerned by the past, by ancestors, and also by other places than this earth...
Such interest and concern may be rooted in actual experience and involvement - from before incarnation; when we were spirit beings.
But, another vital understanding is of Time.
I regard it as a potentially serious error that Christians adopt some version of the idea that all Time is present at one time, that past/ present/ future are actually all one. Such an idea (derived, apparently, from ancient Greek philosophers including Plato) is all-but standard and official theology among Christians; and probably has been since not long after the death of Jesus.
On the contrary (by my understanding); I regard it as intrinsic to the Christian world-view that Time is real; i.e. directional, linear, sequential, cannot be reversed etc...
So past really is past, future is not yet realized - and so forth.
In other words, the 'common sense' idea of time, held by the uneducated and by children, is true.
Such a straightforward understanding of Time is necessary if we are to avoid paradox and incoherence when it comes to the idea of eternal beings that undergo change, development, evolution, transformation - salvation.
If such changes of Beings are to be real - Time must be real.
...Because Time is intrinsic to a Being - a Being is a dynamic thing, because Being is alive and conscious, and motivated.
Plus; the deepest understanding of Freedom entails that our future is Not fixed; but may be changed by our free choices; and this agency is intrinsic to the chosen nature of Christian salvation.
OK. I am making here the point that:
It would be A Good Thing if we became aware that this earthly mortal life we now experience is a stage in an unbounded continuum or sequence of experience in both directions.
We each experienced a real past going back and back; and we confront a real future without limit.
The issue is what we do about this?
Part of it is choosing the future; yet equally, part of it is acknowledging the experiences of our past (recent and remote) - because it is these from which we may learn, and which may transform our being.
And that transformation may - potentially - be positive, and eternal.