In QED, 'electron self energy' to first order results from an electron emitting and reabsorbing a photon. But surely the emitted photon can be absorbed by any other electron in the universe, not just the emitting electron? Indeed it makes no sense to say the photon is absorbed by the same electron, because electrons are indistinguishable. In other words, surely the feynman amplitude is going to be too large by a factor N, where N is the number of electrons the emitting electron can interact with? Is the calculation guilty of isolating an electron-photon system from the rest of the universe? Thoughts anyone?