The version of that story I remember is that John Wheeler said to Feynman that the reason all electrons are alike is that there's only one electron, which we pe

The version of that story I remember is that John Wheeler said to Feynman that the reason all electrons are alike is that there's only one electron, which we perceive as a positron when it's going backwards in time. Feynman instantly refuted the idea by pointing out that there are more electrons than positrons.