Variety

I seem to have loved you in numberless forms, numberless times, in life after life, in age after age forever

Variety's the very spice of life, that gives it all its flavor

There is not so variable a thing in nature as a lady's head-dress

Variability is one of the virtues of a woman. It avoids the crude requirement of polygamy. So long as you have one good wife you are sure to have a spiritual harem