One day the staff members of a zoo called a meeting to discuss the problem--how to deal with the kangaroos that were found out of the cage. They came to the conclusion that the cage was placed too low and decided to raise it from one to two meters high. But the next day the kangaroos were still at large and they again raised the cage to three meters.

Quite beyond their expectation the next morning they saw the kangaroos still free to go about. They were alarmed and determined to go to all the length by raising the cage to the height of ten meters.

Later a giraffe, while chatting with some kangaroos, asked them, "Do you think they will go on raising your cage?"

"Hard to say," said a kangaroo, "if they continue forgetting to fasten the cage door."

(What we can learn from the story is this: Everything has different aspects--one is fundamental and others are incidental; some important and others less important; some urgent and the rest can wait. In this case to fasten the door is fundamental and to raise the cage incidental. Preference for the latter will no doubt lead nowhere)