[ source ]
A guy sticks his head into a barber shop and asks, "How long before I can get a haircut?" The barber looks around the shop and says, "About 2 hours."
The guy leaves.
A few days later the same guy sticks his head in the door and asks, "How long before I can get a haircut?" The barber looks around at the shop full of customers and says, "About 3 hours."
The guy leaves.
A week later the same guy sticks his head in the shop and asks, "How long before I can get a haircut?" The barber looks around the shop and says, "About an hour and a half."
The guy leaves.
The barber who is intrigued by this time, looks over at a friend in the shop and says, "Hey, Bill. Follow that guy and see where he goes."
A little while later, Bill comes back into the shop, laughing hysterically.
The barber asks, "Bill, where did he go when he left here?"
Bill looks up, tears in his eyes and says, "Your house!"