A professor stood before his philosophy class and had some items in front of him. When the class began, without saying a word, he picked up a very large empty mayonnaise jar and proceeded to fill it with different coloured golf balls.

He then asked the students, if the jar was full. They agreed that it was.

The professor then picked up a box of pebbles and poured them into the jar. He shook the jar lightly until the pebbles rolled into the open areas between the golf balls.

He then asked the students again if the jar was full. They agreed it was.

The professor next picked up a box of sand and poured the sand into the jar. Of course, the sand filled up everything else.

He asked once more if the jar was full. The students responded with a unanimous 'yes’.

The professor then produced a jug of coffee from under the table and poured the entire contents into the jar, effectively filling the empty spaces between the sand.

He asked if the jar was full now. The students again had to agree that it was full.

But the professor then produced a jar of sugar, and dissolved spoonful after spoonful into the coffee liquid. The students laughed, realizing they had been fooled again.

"Now," said the professor, as the laughter subsided, "I want you to recognize that this jar represents your life.