There are countless electrons in the universe, and yet they all have exactly the same mass and charge. Why should all the electrons have exactly the same mass and charge?
Richard Feynman, in his Nobel Lecture , tells us of a telephone conversation with another great physicist, John Wheeler.
As a by-product of this same view, I received a telephone call one day at the graduate college at Princeton from Professor Wheeler, in which he said, "Feynman, I know why all electrons have the same charge and the same mass" "Why?" "Because, they are all the same electron!" And, then he explained on the telephone, "suppose that the world lines which we were ordinarily considering before in time and space - instead of only going up in time were a tremendous knot, and then, when we cut through the knot, by the plane corresponding to a fixed time, we would see many, many world lines and that would represent many electrons, except for one thing. If in one section this is an ordinary electron world line, in the section in which it reversed itself and is coming back from the future we have the wrong sign to the proper time - to the proper four velocities - and that's equivalent to changing the sign of the charge, and, therefore, that part of a path would act like a positron."
From Richard Feynman's Nobel lecture, December 11, 1965
The basic idea is that antimatters (such as positrons) can be regarded as matters (such as electrons) traveling "backwards" in time (e.g. from the future to the past). Then, you can conceive the world-line of a single electron traveling in a zigzag manner from the past to the future, and then from the future to the past, and so on and so on, giving rise to all the electrons and positrons in the universe.
The catch is, as Feynman says, that then there would have to be exactly the same number of positrons as electrons. Actually, the universe as we know it is composed mainly of matters, an asymmetry which has not been properly accounted for yet. Despite this catch, Wheeler's single electron universe is a fascinating idea.
Talking of the mind-brain problem, it appears that despite the superficial differences, we all have basically the same form of consciousness. In that sense, there is only one consciousness, like there appears to be only one electron.
Maybe we can conceive a single consciousness traveling in a zigzag manner like Wheeler's single electron in the space-time. Then, of course, we should have an anticonsciousness, whatever it may be.
That is yet to be found, but who knows?