  How the superconductivity in unconventional superconductors emerges from the
diverse mother normal states is still a big puzzle. Whatever the mother normal
states are the superconductivity is {\em normal} with BCS-like behaviours of
the paired quasiparticles in condensation. To reconcile the diverse mother
normal states and the normal superconductivity in unconventional
superconductors, we revisit a proposal that the emergence of the low-energy
coherent parts of the physical electrons, which survive from the interaction
correlations, is an essential prerequisite for superconductivity. The
superconductivity is driven by the pair condensation of these coherent parts of
the physical electrons. Moreover the incoherent parts of the physical electrons
can enhance the superconducting transition temperature $T_c$ although they are
not in driving role in the emergence of the superconductivity. Some
experimental responses of the coherent parts of the physical electrons are
predicted.
