A cellphone rings in her classroom, just as she was explaining the most important concept of her calculus lesson. She was outraged. "Don't you people ever understand that cellphones aren't allowed in the classroom?" she exploded. "What do you people think? School rules are a joke?" A few girls raised their eyebrows. "Next time I hear a cellphone ringing, be assured you won't see it again."
The phone keeps ringing … a monotonous, shrilly and dissonant melody.
"Now, who's cellphone is it?" she cried. "Turn it off at once, before I lose my temper!" Like she hadn't already.
From the serious looks on the faces of her students, a mixture of wild bemusement and apprehension, she realized it had been her own cellphone all along, purring along gently from the depths of her handbag.