Obviously, Wheeler was much more knowledgeable about physics than the likes of me, so my obvious objection must have occurred to him, but here it is. Electrons have mass, so the total mass of a multiple electrons must be more than the mass of a single electron. Or is there some other mind-bender that would explain why "the" single electron appears to have a trillion times it real mass when that electron's timeline ha…
Time travel is required for this thought experiment. The single electron moves forwards and backwards in time so that at any slice of time it can appear at multiple locations simultaneously. Just like a time traveller can go back in time and there would be two of them, this electron travels back and forth in time so that there are numerous instances of it.
When an electron and a positron meet, they annihilate each other. That could be considered the same single particle switching direction in time.