Riddle: You are going to be executed but you are allowed to decide how. The judge says "Make one statement if it is false you will have your head cut off if it is true you will be hung". What statement will save your life?
Answer: "My head will be cut off"
This statement creates a paradox as if your head is cut off then the statement was true and you should have been hanged. If you are hanged then the statement is false and you should have been beheaded.