When the glamour wears off, or merely works a bit thin, they think they have made a mistake, and that the real soul-mate is still to find. . . And of course they are as a rule quite right: they did make a mistake. Only a very wise man at the end of his life could make a sound judgment concerning whom, amongst the total chances, he ought most profitably to have married! Nearly all marriages, even happy ones, are mistakes: in the sense that almost certainly (in a more perfect world, or even with a little more care in this very imperfect one) both partners might have found more suitable mates. But the 'real soul-mate' is the one you are actually married to.