A blonde woman walks into a store and is immediately curious about a shiny object on sale. She asks the shop assistant, ‘What is that?’ The assistant responds, ‘It’s a thermos.’ The blonde then asks, ‘What does it do?’ ‘It keeps hot things hot and cold things cold.’ So the blonde buys one. The next day she brings the thermos to work with her. Her boss, also a blonde, asks, ‘What is the shiny object?’ ‘It’s a thermos.’ ‘What does it do?’ ‘It keeps hot things hot and cold things cold.’ Her boss then asks, ‘What do you have in there?’ The blonde replies, ‘Two cups of coffee and a Popsicle.’
The version I heard of that joke:
Three people sitting around and the subject comes up, what’s the most amazing invention ever, and the blond says “thermos”. And she explains: “It keeps hot things hot and cold things cold.... But how does it know?”
After ‘It keeps hot things hot and cold things cold’ I expected the punchline to be “But how does it know?”...