Didn’t Pencil In A Surprise

(My mom and I are waiting at the Department of Motor Vehicles. Since we know it’s going to be a long wait, we’ve brought number puzzles to pass the time. We know each other very well and can often predict each other’s actions. When one of us has correctly predicted something, we usually tell the other.)

Me: “I forgot a pencil. Do you have an extra?”

Mom: *holding a purple pencil and a silver pencil* “Pick whichever one you want.”

(Though I would normally pick the purple pencil, I take the silver one. My mom takes the other without looking at it.)

Mom: “I knew you were going to take the purple one.”

Me: “You mean the purple pencil that you’re holding?”

Mom: *looking down at her pencil* “Oh. I guess I should have checked first.”