The above is a live issue for me - because several of the thinkers on religion whom I most respect believe in (some version of) reincarnation - that is, of a 'system' by which people have more than one mortal, incarnate life.
Reincarnation is, indeed, apparently the usual belief of tribal 'hunter gatherer' peoples, who generally believe that souls are of a fixed number but may be re-born, and/or may transform to and from souls of animals and other beings; so it may seem that some intuition of this kind is 'built-into' human beings.
I suspect that what is actually built-in, but to degrees varying between individuals, is the sense or memory that our personal, individual life did not begin with our conception or birth; but that we had a previous existence before we were incarnated (i.e. before we got a body).
This, for me personally, is a basic datum; it is a solid feeling - that I personally existed before the time I had this mortal life and body.
But how to interpret this basic datum of pre-existence is where the major disagreement comes-in.
The usual idea among intellectuals in this modern corner of the earth over the past couple of hundred years is that this datum of pre-existence either does not exist or else that it is a delusion derived from wishful thinking, primitive and unscientific world views, immaturity, manipulation by ruling elites, or something or another... merely incoherent nonsense without any actual, or even possible, factual or evidential basis.
I am quite happy to acknowledge that the pre-existence datum is not universal to each and every individual; in the sense that many/ most people apparently cannot remember how differently they thought as a child, and many people apparently cannot introspect, and many people are dishonest; and quite a few people suffer from mental pathologies of various kinds, some of which so dominate their minds that they cannot be clear about much else...
Leaving that aside, my personal conviction is that this pre-existence datum is true; and/ but also that this, here-and-now, is the first and only time I have lived on earth with a body - this is my only incarnation.
Such is, indeed, the standard Mormon view which convinces me on intuitive grounds and by personal revelation; but it is perhaps unique among the overall majority of mankind of the past and present (Hindus and Buddhists for instance) who assert multiple reincarnations, and the majority of Christians who have asserted that our personal life was created by God from nothing at some point at or between conception and birth.
Like the tribal hunter-gatherers, Mormons tend to regard pre-existence as a datum - so that our essential souls or spirits or selves 'always have been' in some form or another, before they are incarnated. It follows that at any point some souls, spirits, selves are not incarnated - this perhaps being the basis of the 'spirit world' of the unseen.
There is disagreement over whether, or how, these non-incarnated spirits are present in this world, and the possible extent of our interaction; but my current understanding is that pre-mortal spiritual life is engaged with mortal life on earth - that these spirits are present and involved; and that is, I think, why some people (so many people) have a sense of having lived before their current lives, a sense of having lived in the past.
In other words; the datum is (I think) having been alive before this incarnation, and present and engaged with earthly life; but there is a difference of interpretation of this datum with some people (who believe in reincarnation) feeling that the datum implies past incarnate mortal lives; while other people (such as myself, and some Mormons) believing that the datum is due to our previous spirit existence being active in earthly affairs.
But whether as pre-mortal spirits or in previous incarnations; what may be the purpose of our prior involvement with earthly affairs? In principle, the reasons might include that we were present: 1. As servants, for the good of the mortals alive in that era; or 2. As learners, gathering experiences aimed-at our own long-term spiritual progress.
Or both. We may have been 'angels' - i.e. spirits who were helpers and messengers of the divine; and we may also have been experiencing, learning and becoming more spiritually advanced.
(And there is, of course, the dark side to be considered. As pre-mortal spirits, according to what seems to be given in Christian scriptures and revelations, some unincarnated spirits are evil anti-angels - actively intervening in mortal life but against the divine plan: hinderers rather than helpers. And some mortal incarnates also take the same side.)
Anyway - my point here is that If we agree on the truth of the datum of a reality-based sense of our personal pre-existence and involvement in earthly affairs; then there can be agreement that each of us has direct knowledge of previous eras (times and places) based on our own experiences.
Note: a further disagreement about the datum concerns the extent to which our pre-existence was defined. Some assert that pre-existence may include having lived as non-human entities, or as humans of the other sex; whereas my intuition is that we have 'always' been Men in general and men or women in particular; and that feelings of qualitatively-other identities are due to us having worked-with e.g. the other sex, animals, plants, minerals... rather than having actually-been e.g. the other sex, animals, plants, minerals. The confusion (as I interpret it) arises from our pre-mortal unincarnated and spiritual nature; which was less bounded, more overlapping, and with a much less-fully-differentiated 'self'.
