Caller: “Why does the automated system say it can’t find my card!? I’ve been complaining about this for months now, and I’m really disappointed it isn’t fixed!”

Me: “Sorry to hear that. Let me see what I can find. Can I have your card number, please?”

(The caller reads off 12 numbers.)

Me: “And the last 4?”

Caller: “Oh! You need all 16? Do you suppose that’s why it couldn’t find my account?”