Me: [on phone to Elder Sister] "Oh, I found this book at the library called 'Is Pluto a Planet?' I may have left a slip of paper inside answering yes..."
E.S.: "Pluto isn't a planet."
Me: "Yes, it is. It's a planet."
E.S.: "It is a planet, and it isn't a planet."
Me: "It can't be both a planet and not a planet, [E.S.]."
E.S: "It's Schroedinger's planet!"
Me: "Schroedinger's planet...populated by cats?"
E.S.: "We don't know. Not until they're observed."
Me: [hastily changes subject]