Talk to the computer in verbs and nouns

You just did what Lauren did, and then Jim Lovell

P01 is a prelaunch program. Selecting it mid-flight makes the computer start initialising as if it were sitting on the pad, and the navigation data it had been keeping is lost.

Margaret Hamilton's young daughter Lauren did exactly this while playing with the simulator at MIT, and it crashed. Hamilton wanted to add protection to the flight software. She was overruled: astronauts were trained not to make mistakes. A note went into the documentation instead: do not select P01 during flight.

Then, on Apollo 8 in December 1968, on the way home from the Moon, Jim Lovell selected P01 by accident. The navigation data was wiped, and the MIT team worked out how to restore it. Hamilton later used the story to argue for software that protects itself against human error, which is part of what she meant by software engineering.