According to my smartest friend, Wikipedia, many people mistakenly assume that the term Moonshine comes from the fact that illegal brewers of alcohol work at night, or under the light of the moon. However, it is actually a synonym for "nothing". "Mere Moonshine" is something that can't be held or touched and can barely even be seen. It is, "A matter or mouthful of moonshine; a trifle, nothing." So, when an illegal maker of alcohol is asked what all of that equipment is for he might respond, "It's nothing. It's just moonshine."
Quite a sad song which, given the last couple of lines, could have also been used during Hell Week. I just didn't think of it.