I love the little quips that Knuth adds to his writings. There are little subtle things that have to be there to be funny and just below the surface meaning of

I love the little quips that Knuth adds to his writings. There are little subtle things that have to be there to be funny and just below the surface meaning of the text, because taken literally they would be absurd. I remember seeing a couple in there and a couple in his book Concrete Mathematics.