From Winnie the Pooh

If the person you are talking to doesn't appear to be listening, be patient. It may simply be that he has a small piece of fluff in his ear.

"Rabbit's clever," said Pooh thoughtfully.

"Yes," said Piglet, "Rabbit's clever."

"And he has Brain."

"Yes," said Piglet, "Rabbit has Brain."

There was a long silence.

"I suppose," said Pooh, "that that's why he never understands anything."