Patient: "Normally, I wouldn't tell you how to do your job, but there's only one thing I like that works for my depression."
Intern: "What's that, sir?"
Patient: "Dilaudid." (very strong painkiller for non-medical people).
Intern: "Sir, that can actually cause depression."
Patient: "Like I said, not trying to tell you how to do your job, but it works well for me. Might be my chemistry is different."