More accurately, his secretary (as per https://cs.stanford.edu/~uno/email.html https://cs.stanford.edu/~uno/email.html). As per https://www.quora.com/What-is-i

More accurately, his secretary (as per https://cs.stanford.edu/~uno/email.html https://cs.stanford.edu/~uno/email.html). As per https://www.quora.com/What-is-it-like-to-be-Knuths-secretary https://www.quora.com/What-is-it-like-to-be-Knuths-secretary, the secretary role has changed a couple of times in the last couple of years.