In 1937 I. I. Rabi proposed the unusual idea of the muon being only an excited electron based on which investigation of muon-electron conversion began. The Lepton Flavor Violation theory expects decay of the muon into an electron and muon neutrino/antineutrino pair. The MU2E experiment being in preparation in Fermilab is a very challenging new physics’ experimental idea with possibilities to be complementary with LHC muon investigations and to help answer Rabi’s questions about the physics of flavor and lepton generations.