Science knows very little regarding our consciousness or the "I" or "self" as you put it.
For instance,
Trillions of our cells die and get replaced regularly- when our cells are replaced, does this mean "I" am no longer "me" ? Do you think consciousness resides in my brain? If so, please enlighten me which group of brain cells contain consciousness. What if I lose a leg; will I lose "some" consciousness? Is a single cell self-aware?
If cells in my hand are self-aware, why am "I" still able to slap myself in the face? Surely my "self-aware" cells in my hand would refuse to partake in such self-destructive behaviour.
Research on near-death experience suggests consciousness can exist outside the dead body.
