Clever theme, not least because it requires thinking about.
The meaning of lyrics is usually open to interpretation, and usually lost on me and I suspect most listeners.
Steely Dan, for example, could be advocating genocide and organised child abuse and few of us would realise it.
Gary Puckett's Young Girl may well be about having underage sex, but it could also be relative - an older man falling for a much a younger woman.
Anyone who can genuinely understand Zappa is a brighter person than me.
I reckon there's an element with him of the Emperor's New Clothes - he's laughing at all of us.