Sorry, Radio Flyer.

I was looking at your question from a totally different perspective! So, you just want to know without reference to illness; wow, good question, when you look at it that way.

I have NO idea! It seems to me though, as humans, it is intrinsic to respond to desire. Without it, what else would make us drive our species forward (and not just as respects sex)? I think we are built to want. But to want "nothing." As you said: hmmm...