Sheldon: [cell phone rining] Oh, dang it. Hello, Mother.
Mary Cooper: Hi there, Shelly. You will never believe who I ran into at the barbecue festival.
Sheldon: I am right in the middle of some very important work. I don't have time for this right now.
Mary Cooper: Then why did you answer the phone?
Sheldon: Because you raised me to be polite. Now stop bothering me. [hangs up]