This may seem weird, but I have to say it because I think it applies to a situation like this: I have been reading the philosophy of these philosophers, considered generally as "postmodern" philosophers: Deleuze and Guattari. They have a very interesting metaphysics of how the world works. They liken it to a rhizome. This holds in many different things in life: but in this situation it seems to apply to what it is to be an individual. It is not a tree, a singular entity from which roots and branches diverge. It is an "assemblage" that forms a network with all sorts of other entities: both socially and biologically. Such cases highlight the difficulty of even finding the "stem" or "tree trunk" of what it is to be an individual, a subject. It is not so neatly defined. There are so many things, biologic and environmental and cultural, that go into making a person (roots), and so many things that come out of it (branches)- a chaotic network of stuff, many of it even contradictory. And like a living rhizome, it is constantly dynamic and shifting.
I have found this to be a very enlightening and even therapeutic way of thinking about the self, about ideologies, about identities, about meaning in life, etc, etc...
en.wikipedia.org
Addendum: BTW, this seems very much to converge on some of the insights from Buddhism, and its ideas of Anatta (the no-self, not as an individualistic ego- but a nodal point merging in all directions with the rest of the universe).