Giuseppe Tomasi Di Lampedusa said this quote

Those were the best days in the life of Tancredi and Angelica, lives later to be so variegated, so erring, against the inevitable background of sorrow. But that they did not know then; and they were pursuing a future which they deemed more concrete than it turned out to be, made of nothing but smoke and wind. When they were old and uselessly wise their thoughts would go back to those days with insistent regret; they had been days when desire was always present because it was always overcome, when many beds had been offered and refused, when the sensual urge, because restrained, had for one second been sublimated in renunciation, that is into real love.