Recently, someone told me a knock-knock joke, and I deemed it offensive and insensitive. The subject matter was itself not offensive, and neither was the punchline, unless you consider bananas, oranges, and forced puns offensive. However, after the recent unwelcomed assault of jokes knocking on my conscience’s door, I’ve concluded that the genre of humour known as knock-knock jokes is, as a whole, entirely offensive from the first knock to the last announcement of who is at the door.