Wheeler invoked this concept to explain the identical properties shared by all electrons, suggesting that "they are all the same electron" with a complex, self-intersecting worldline.
Quantum mechanics is so cool!
If I remember correctly, Feynman quickly suggested to Wheeler that this is probably wrong, as it would imply that there are as many positrons as electrons. At least in our little piece of the universe, this is definitely not the case.
Maybe we haven't seen the positrons yet because they're still traveling back in time from the future!
Showing that this makes no sense is left as an exercise to the reader.
If the universe has toroidal topology, then the Big Bang is connected to the Big Crunch, and the number of positrons doesn't have to equal the number of electrons.