Sidney is cruising along the highway when his car starts misfiring and losing power before finally stalling for good. He steers it to the side of the road and tries to restart the engine without any luck. He calls AAA whose service man arrives a short while later, listens to his account of the car’s failure and lifts the hood to start work.
As he knows nothing about engines, Sidney wanders off a little way for a smoke. As he is returning to his car, the engine suddenly starts and runs without a single misfire or puff of smoke from the exhaust.
“Brilliant!” declares Sidney. “You fixed it! Was it easy?”
“Yeah’, says the mechanic. “It was nothing serious. Just shit in the carburetor.”
Sidney thinks for a second and says “OK, how often should I do that?”