Once a professor entered the classroom with a glass jar, rocks, pebbles, and sand. The students were amused to see what he was up to. First, he started filling the rock parts into the jar until he couldn’t add any more.
He asked the students if the jar was full and everybody nodded yes. He then started putting the pebbles inside the jar which went inside through the small gaps and he shakes the jar to allow the pebbles to get into those vacant spaces in between the rocks.
He asked the same question to the students and they again said that the jar was full. Finally, he poured the sand inside the jar which went through the minute gaps and got filled in the jar.
The professor explained that this is how you should set priorities in life. Rock is like your family, while pebbles are like your career while sand is like the least priorities in life and unnecessary quarrels and egos.
If you put sand on the jar first, it will get easily filled up leaving no space for rocks and pebbles.
Moral: You should identify your priorities in life and develop a good strategy to work towards fulfilling it rather than wasting your time and effort on unnecessary aspects of life.