What does "normal" mean? It's not normal in the sense that we are "supposed" to be attracted to the opposite sex in order to procreate and keep our species alive. In that case it's kind of the opposite of normal. Then again, maybe it is normal because it acts as some sort of minor population control mechanism since not everyone has the desire to procreate? :P
Anyways, it could be changed. Anything about us humans can be changed.