We show that hydrogen bond (O:H-O) possesses memory (Panel a, H-bond linear velocity derived from measurements) to emit energy at a rate depending on its initial storage and that water skin exhibits supersolidity (b, Raman confirmation) to grade thermal conductivity with heat flowing outwardly.These identities resolve intrinsically the Mpemba paradox-(c) hotter water freezes faster than colder water does with (d) skin being warmer than the bulk.Heating stores energy into water by stretching the O:H nonbond and shortening the H-O bond via Coulomb coupling; cooling does oppositely, like releasing a highly deformed bungee, to emit heat at a rate of history dependence.Skin molecular undercoordination grades the local mass density, specific heat, and thermal conductivity, favoring heat outward flowing.Convection alone creates no Mpemba effect.Being sensitive to the source volume and the drain temperature, Mpemba effect proceeds only in the strictly non-adiabatic source-drain interface with a relaxation time that drops exponentially with the rise of the initial temperature of the source.Reproduction of the Mpemba effect (c, d) verified the validity and consistency of our recent findings on the structure order, O:H-O bond potentials, and physical anomalies of water ice [1-6].