think on this.

» Are there asexuals among us? On the possibility of a "fourth" sexual orientation (Scientific American)

psychotherapy:

…According to Brock University psychologist Anthony Bogaert, there may be more genuine asexuals out there than we realize. In 2004 Bogaert analyzed survey data from more than 18,000 British residents and found that the number of people (185, or about 1 percent) in this population who described themselves as “never having a sexual attraction to anymore” was just slightly lower than those who identified as being attracted to the same sex (3 percent). Since this discovery, a handful of academic researchers have been trying to determine whether asexuality is a true biological phenomenon or, alternatively, a slippery social label that for various reasons some people may prefer to adopt and embrace.

Sexual desire may wax and wane over the life course or—as many people on antidepressants have experienced—become virtually nonexistent due to medications or disease.