A professor stood in front of his philosophy class with some objects lined up on the table in front of him.
When the lesson started, he showed them a very big and empty glass jar and started to fill it to the brim with golf balls. He asked his students if they thought the jar was full. The students all agreed that yes, it was.
Then the professor took out a box of gravel and poured it into the jar. He shook the jar lightly and the gravel rolled down into all the little spaces between the golf balls. Again he asked his students if they thought the jar was full.
Again they said, that yes it was.
He then took a box of sand, and emptied it into the jar. Of course the sand filled up the rest of the space. Once again the Professor asked if the jar was full, and all the students answered loudly "yes!".
The Professor then took out two cups of coffee that he had been hiding under the table, and poured the contents into the jar.
The students laughed. "Now" said the Professor, "I want you to remember that this jar represents your life".
"The golf balls represent the important things: family, children, health, friends and other things you keep close to your heart. Things that, if everything else was lost, would still enrich and fill your lives.
The gravel represent the other things that mean something, like a home, a job, a car. The sand represents everything else".
"If you start out by filling the jar with the sand" the Professor continued "you wont be able to fit in the golf balls and the gravel. Life works the same way. If you put all your energy into the small things, there is no space left for what is important to you. So... spend time with your children, take your partner out for dinner, meet up with your friends. Spend some time every day with your hobbies. There will always be time to clean the house and everything else - just make sure you look after the things that really matter to you first! The rest is just sand..."
One of the students raised his hand and asked what the coffee represented. The Professor smiled. "I am glad that you asked. The coffee is there to show you, that no matter how full your life feels, there is always room for a coffee with a friend".