Over a hundred years later, I get the joke.

In Alice in Wonderland, Lewis Carrol writes:

"Then you should say what you mean." the March Hare went on.

"I do," Alice hastily replied; "at least -- at least I mean what I say -- that's the same thing, you know."

"Not the same thing a bit!" said the Hatter, "Why, you might just as well say that 'I see what I eat' is the same thing as 'I eat what I see'!"

It's an alimentary course in logic.