This question popped out of another discussion, about if the photon needs a receiver to exist. Can a photon get emitted without a receiver? A universe containing only one electron was hypothetically suggested. And a similar theory was mentioned in Feynman’s nobel lecture in 1965:
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." "But, Professor", I said, "there aren't as many positrons as electrons." "Well, maybe they are hidden in the protons or something", he said. I did not take the idea that all the electrons were the same one from him as seriously as I took the observation that positrons could simply be represented as electrons going from the future to the past in a back section of their world lines. That, I stole!
It was a very successful theft indeed, so let me try a theft too. Since Wheeler came up with this theory, we have come up with string theory that create electrons and other elementary particles by string vibrations. Could all strings also have equal properties or interactions, so they can create different particles with equal charge and mass? So if we merge Wheeler’s idea with string theory, we can formulate this into a hypothetical question: Could all strings be one single string which weaves the fabric of the universe? To simplify it even further we can say that a single particle drags the string along and tie the knots in the fabric of the universe together by interactions with itself. So then we get a single string or a single particle universe, which is the ultimate simplicity.
The speed of light can’t be a threshold for such a particle; because the particle itself must travel with infinite speed far beyond C and probably don't even have a velocity we can put any number on, but just call infinite speed. To go past the speed of light the particle must be without mass, and then it has no inertia and is free to go everywhere to interact with its own string which is woven into time, space, particles, mass, charge, magnetism, gravity, me, you and the universe itself.