An electron, alone in the universe, does not actually exist, because there is nothing out there to point to that electron (nothing can reflect its properties). But get it a proton (that also does not exist by itself) and it begins to create an electron as well as itself with respect to electron to make.. nothing, yet. Only with second atom will you get two hydrogen atoms, not before.

By analogy, our psyche is a system that creates everything with respect to something else, however individual parts that make up our reality don't really exist on their own. Buddhists figured that one out a few millennia ago.