A police officer sees a drunken man intently searching the ground near a lamppost and asks him “What are you doing?”. The drunk replies “I lost my car keys. I’m looking for my car keys.”
So… the police officer helps the man search for a few minutes without success. Then he asks the man, “Sir, are you *sure* you lost your keys here?.”
“No,” is the reply, “I lost the keys somewhere across the street.”
“Then why are you looking here?” asks the surprised and irritated officer. The drunk replies, “Well duh.. The light is much better here, of course!”