>>>>Peter Sellers used to have good ones on this subject:
>>>>
>>>>- Can you tell me what time is it?
>>>>
>>>>- Yes, I can.
>>>>
>>>>- Thank you.
>>>>
>>>>Similarly,
>>>>
>>>>- Do you know where Grand Hotel is?
>>>>
>>>>- Yes, I do.
>>>>
>>>>- Thank you.
>>>
>>>More Peter Sellers:
>>>-Does your dog bite?
>>>-No.
>>>-Aaaarghhh!!!
>>>-That is not my dog.
>>
>>SNAP! See my reply too!
>
>Yes, I saw it. This reminds me of a temporary teacher I had when I was a teenager. One of the first things he told us, was always to listen thoroughly to questions before we answered. A few minutes later he asked if anyone had forgotten to do their homework. When a few pupils told him that they had in deed done their homework, he looked at them with a look that made them search for holes in the floor. After a few minutes more he asked us if anyone knew what time it was, and a few pupils shouted the correct time. Then he reminded us that he did NOT ask how much the time was, which of course made the pupils very embarassed. I can tell you that I was not the only one who learnt a lesson that day, and our respect for this teacher increased dramatically.

Not for the same reason but your message reminds me of an anecdote (true story) our form master once told us. It was about a guy giving a lecture on observation. During the course of the lecture he drifted onto the subject of urine being harmless to ingest and, to prove it, he dipped his finger in a jar of urine he had, and sucked his finger. He them passed the jar around the auditorium for everyone to have a go, which they did. When the jar had done its rounds and returned to him he got back to the original subject: "Now, ladies and gentlemen, on the subject of observation, you should have noted that I dipped my second finger in the jar but sucked my index finger"