The following text relates to an exercise that a professor of psychology presented to his students having in front of him some objects to point out the importance of the distribution of time in our lives in relation to what really matters.
Without saying anything, he took a jar and began to fill it with ping pong balls. When no more could fit, he looked at the students and asked if the jar was full, and they said it was. Then the teacher took some pebbles and he started pouring them in the vase, shaking it, filling the void between the ping pong balls. When no more pebbles could fit, he asked the students if the jar was full and they, somewhat bewildered, said that it was. Then, the professor took sand, threw it into the jar and filled all the gaps between the pebbles. He asked the students again if the jar was full, and they answered "yes!" Then the professor got two cups of coffee from under the desk and poured them into the jar while the students were laughing, puzzled.
"Now," said the professor, "I want you to imagine that the jar is your life. The balls represent the most important things in your life, things that even if all others are lost, are capable of fulfilling your life. The pebbles represent less important things, and sand matters of even lesser importance. If you first fill the jar with sand, there will be no room to put the pebbles and the balls. The same applies to your life. If you spend your time and energy on little, unimportant things, you will not leave room and you will not have the time and energy needed for people and matters of bigger importance. Make sure to add the balls first, then the pebbles and finally the sand».
A student told him: "You forgot about the coffee ... What does it represent?”
“The coffee represents enjoyment. No matter how full your life is, there will always be room for a coffee with a friend", the professor said with a smile. "When your everyday becomes overwhelming remember the jar and the two cups of coffee”.