Principles of Economics Class, Doherty Lecture Hall, CMU.
Lottery numbers for all the students are listed on either side of the room, A to L on the left, M to Z on the right:

Student #1: [yells to student entering room] YO CORNBREAD! YOU’RE ON THE LEFT!!
Student #2: Wait. What are you talking about? His last name is Roberts.
Student #1: Oh right! I was thinking that his last name was Bread from calling him Cornbread.