If a listener nods his head when you're explaining your program, wake him up.

Perlis—1922–1990: a founding father of computer science as a separate discipline". p. Perlis was elected to the National Academy of Engineering in 1977.

Alan Jay Perlis (April 1 1922 – February 7 1990) was an American computer scientist known for his pioneering work in programming languages and the first recipient of the Turing Award.