Mom sang herself lots of kid songs and folk tunes on the drive over here to keep herself company.
"When I was singing Farmer and the Dell, I got confused! I think I got to cheese, and I couldn't remember what cheese does!" Of course, we all know, the cheese stands alone. Which is Thing 1 about this song.
Thing 2 is the transition of child taking the dog to dog taking the cat, at which point you begin to question the farmer's relationship to his wife, and the wife's relationship to her child, and the child's relationship to its dog. The companionship/food-chain continuum is one we are taught not to question as kids.