A guy sticks his head into the barber shop and says, "How long till I can get a haircut?"
The barber looks at his shop full of customers and says, "Come back in 3 hours."
The next day, the same guy comes back to the barber shop, sticks his head in the door, and asks, "How long till I can get a haircut?" Again, the barber looks around his shop full of customers and replies, "About 2 hours."
For the third day in a row, this same guy comes back to the barber shop, sticks his head in the door, and asks, "How long till I can get a haircut?" The barber now getting frustrated replies, "Come back in an hour and a half, and I'll take care of you." The man leaves.
The barber turns to a waiting customer and asks, "Can you follow that guy, see where he goes? He comes here every day asking for a haircut but never returns." The customer leaves and follows the man.
He returns 15 minutes later and says to the barber, "Your house."