The concepts of self, other, and world are figments of each of our imaginations.

Repeat after me, "I am a figment of my imagination!" A skin cell has no cognitive ability, so cannot have concepts of self and other and world. We possess cognition, and our brains function as pattern recognizers, so we can conceptualize self, other, and world. But this cognition is merely patterns of neurons firing within our skull. Like a computer simulation, it has no external reality. Our ability to conceptualize self, other, and world does not distinguish us from the skin cell that cannot do so. Like the skin cell, each of us is significant only in the effect that we have on the larger thing that contains us.