His friend, Mansour, comes to visit him and sees Nasruddin on his hands and knees, crawling on the sidewalk under the street lamp, obviously searching for something, appearing frustrated.
Concerned for his friend, Mansour asks, "Nasruddin, what are you looking for? Did you lose something?"
"Yes, Mansour. I lost the key to my house, and I’m trying to find it, but I can’t."
"Let me help you," responds Mansour.
Mansour joins his friend, kneels down on his hands and knees, and begins to crawl on the sidewalk under the street lamp, searching.
After a time, having looked everywhere on and around the sidewalk, neither Nasruddin nor Mansour can find the lost key. Puzzled, Mansour asks his friend to recall his steps when he last had the key, "Nasruddin, where did you lose the key? When did you last have it?"
"I lost the key in my house," Nasruddin responds.
"In your house?" repeats the astonished Mansour. "Then why are we looking for the key here, outside on the sidewalk under this street lamp?”
Without hesitation, Nasruddin explains, “Because there is more light here . . . !”