We humans are one of the sexiest animals on earth. Women do not have an annual estrus as do many mammals, but ovulate every month. Men, in their prime at least, are pretty much ready anytime. Further, where most animals copulate for the purpose of reproduction, humans copulate largely for pleasure.

One theory to account for this phenomenon is that it came about because of the helplessness of the newborn human, and the lengthy period of training the infant needed until it could fend for itself. This meant that its chances of survival were greater if the male stayed with the female in something of a pair bond. That way, the male would share in the feeding and the protection of the young through its period of training and development.

To effect this pair bond, however loose it may have been at times, some anthropologists theorize that we evolved a biology that entailed the possibility of ongoing and frequent sexual activity as an enticement, which may even have led to what we now regard as romantic love. This kept the couple together and increased the survival chances of the offspring.

Whatever its origins, the current propensity of humans for frequent sexual activity is undeniable. And most often, when this propensity begins to fade with age, there is a certain sadness in us. Because, up to this point, frequent sexual activity has, over the years, been a source of pleasure for most of us, and for some, a source of love renewal and soul bonding. And as we get on in years, as we feel the drive slipping away, the intensity dying off, it is like the tolling of a bell for what has been a beautiful aspect of our lives.