A Here's Your Sign
Someone I know who I saw yesterday told me this story. Well both him, our friends and me do reenacting (WWII, WWI and American Civil War), and always get stupid questions, but I think this one tops the cake. He was telling me they were doing an event, and they made a camp fire, and a woman said "Wow, is that a real fire ?". He then told her "No lady, it's just an optical illusion. Just put your fingers where you think the fire is. Here's your sign".