Patient: "I need some penicillin."
Me: "Why? What's bothering you?"
Patient: "Nothing's wrong. Penicillin just makes me feel better. I bought it over the counter all the time in Mexico."
Me: "I only prescribe antibiotics when they're necessary, when there's an infection."
Patient: "Doctor, you don't understand. I take penicillin like candy!"
Me: "That's exactly why I'm not going to prescribe it for you."