The Overeager Servant

A master told his servant: "Lock the door."

The servant locked it.

Uncertain whether the master had heard the click, the servant announced: "The door is locked."

"Lock the door," the master repeated, not having listened.

The servant, wishing to obey, tried to lock it again. The lock, already thrown, jammed. The door could not be opened until a locksmith came.

A wiser servant would have simply checked the door and said: "It is locked."