After the preface to The Art of Computer Programming is the Procedure for Reading This Set of Books.
Step 4 is to begin reading Chapter N, with the specific instruction to "not read the quotations that appear at the beginning of the chapter." (emphasis his).
This section is present in the 1997 3rd edition of Volume 1, but not in 3rd edition of Vol 2 or 2nd edition of Vol 3 both dated 1998.
I have guesses as to why this curious instruction exists, but I've been unable to find any reference to it. Does anyone first hand knowledge about this, or a link to info?