Three motorcyclists are arguing as to what is the fastest thing in the world. "It's light" says the first one. "when you switch on your headlight, it illuminates all the road - but you don't actually see the light beam go out, it's so fast". "No" says the second one - it's thought. When your brain tells you what to do, you dont actually feel the message going to your muscles". After a pause, the third one says "No, your both wrong. The fastest thing in the world is diarrhoea". "How do you make that out", exclaim his mates. "Well", says the third one, "I was blatting down this country lane last night when a car came round the corner on the wrong side of the road - and before I could dip my headlight or think to put the brakes on, I shit myself".
