I love the joke from that one batman movie. Two insane people break out of an asylum from the rooftops. They are able to jump across the first few gaps where the buildings are close enough but soon they hit a large gap. One says "i have an idea ill shine my light and you can walk on the light to the other building" and the other replies "are you crazy? How do I know you wont turn it off as soon as im half way across?".
Im sure i butchered it a bit but you get the idea