carbon copies?

how similar are we all? how different are we? if we look deep within, to the core of our soul, are we fundamentally identical? i can't stop wondering. is it merely that we are roughly the same, and therefore can relate to each other in moments that we understand? or is it that we are really identical on the core, and just have different ways of expressing ourselves to others?

(seeking food for thought. i.e. food for further thought, since this may, in itself, count as food for thought.)