Paul Hilfinger is famous for answering student emails in the middle of the night. No one seemed to know why he was awake that late.
So I went to his office and asked him.
When he was an undergrad, computer time was hard to get. That was back when computers were big mainframes, and undergrads were at the bottom of the priority list.
So he decided to go to the computer lab in the middle of the night, no one was using them.
He figured he’d fix his sleep schedule after graduating.
But then he went to grad school, and kept it up.
Before he knew it, he was a professor and could set his own schedule. So now he has no morning classes.