user
Given a cartoon image and a caption. Caption: So a doctor walks into a bar—this is not a joke by the way. Question: Generating an explanation of why this image/caption combination is funny. Answer: 
assistant
"So a doctor walks into a bar" is often the beginning of a bar joke --- but here, the doctor is physically injured and telling his patient about it. We can deduce that the doctor must have walked into a literal physical bar of some kind, and experienced these injuries as a result.