Dan was the doorman of a club in a big city. Everyday, thousands
of people passed his door, and a lot of them stopped and asked
him, "What's the time, please?"
After a few months, Dan said to himself, "I'm not going
to answer all those stupid people any more. I'm going to buy a
big clock and put it upon the wall here." Then he did so.
"Now people aren't going to stop and ask me the time,"
he thought happily. But after that, a lot of people stopped, looked
at the clock and then asked Dan, "Is that clock right?"