Individuality, identity, the self, the very body in which we inhabit, even in its ontology, much less its existential significance, is no more than a hilarious prank which the cascades of Darwinian selection have played on us. One does not need to look any further than the groups of friends beside them or up towards the flickering expanse of the vast infinitum lying beyond the night sky to feel that familiar dread peering. It can even be an exercise in numbers. There is everyone, in the range of some eight billion, then those you may know, or those who may know you, perhaps in the thousands, and now those you care deeply about whom you may call your friends, and finally yourself, where there is only one of.
Sonder is the neologism coined for this particular realization, that there exist this many lives, all of which are just as complicated as your own, each with assortments of acquaintances, families, lovers, pets, mysterious rashes, and late-night guilty pleasures, nearly all of whom have far too many loved ones to celebrate or mourn your life. And even if you, in your unyielding grit, have found purpose as a part of a greater humanity against the nothingness, the everythingness of this backdrop that is our universe, despite being less than nothing, this should at least be a reminder of how meaningless we really are, even within the minuscule bounds of our perception.
This egocentric view that we consider to be almost a priori is, adorably, laughably, pointlessly, no truer than the biblical geocentrism we had accepted, no matter how much we want to believe it. There is nothing for you, no teleology, no reason, no care. You exist, and that is all that is given. The sooner you can accept this, the sooner you can be free.