Atoms are the building blocks of everyone and everything we see. They are everywhere in multitudes that cannot be comprehended by our current abilities.
It has been stated that atoms that are currently forming our being may have come from universe billions and billions of years ago, shaping new forms. Those forms cease to exist and the atoms move on to be something else. We could have the atoms of many of those that have existed before us. Think about the possibility that you might have Einstein, Jefferson, Washington, John Wilkes Booth, or any other possible combination of atoms from some other entity.