All humans feel identification with their own bodies, we all can think independently and feel like an individual. This is probably because big animals (some think that only humans) have consciousness, but consciousness is a really weird concept.
"You" set apart yourself from other things, you are not the door in front of you, you are not that dog in the corner, not even another human. The limits of you can de easily define as everything that "you" can control with your thought, but then there's a lot of things that "you" can control, for example, your heart or the unconscious.
So we can say that "me" is just everything that I feel as myself, everything connected to my nervous system. Then "me" is not a static thing, there's a lot of "me" that die yesterday and a lot of "me" that isn't yet me. We fall in a paradox, specifically Theseus's paradox.
How can I be the same person if all my atoms were replaced at some point? Am I also all things that once were me? Is consciousness just an illusion?
I can't stop wondering this.