"Mother, I require a favor of substantial magnitude."
"It's an analogy. The tuna is both cooked and raw until you open the casserole lid."
"She doesn't know we're living together yet. Or that I'm pregnant. Or that you're nineteen."
They both laugh. For a moment, Sheldon isn't the weird kid. He's just a scientist talking to another scientist. The Cooper house. Georgie is trying to hide Mandy's pregnancy pillow while Mandy pretends to be "just a friend helping with the tires." Mary serves iced tea to Mandy's mother, who looks around suspiciously.
"So I must prove myself. With hardware."
"The closet you got banned from after you tried to build a cloud chamber using dry ice and a stolen cafeteria tray?"