from a psychic point of view, life is a succession of Subjective personal experiences, animated by elements from within and/or from without. these experiences by definition are Human, e.g. occur into/upon mankind, and they could be of a rational as much as irrational structure.
all experiences there is must be (to my mind) unlimited and very variant, since the human mind is not a recent conception, on the contrary it is a very ancient landscape which had inhabited numerous populations through many periods of time (our memory holds alot of what had been lived before, but we cannot actively recall)
among our own experiences of living, some experiences are definitely of very common nature and very relatable to most individuals of our specie – human kind. But in the other hand, other experiences are very much less prevalent, or are highly personified/individualized, which makes them by default either hardly communicable, i.e difficult to transform into a social language, or hardly perceivable by different minds, or even each of the 2 at once.
there must be a consensus of opinion between 2 beings about subjective life experiences to be in phase each one another and click, phase shift causes sentiments of aloofness, none belonging and loneliness.