A professor fills an empty mayonnaise jar with golf balls, pebbles, and sand to demonstrate to students how to prioritize the important aspects of their lives. He fills the spaces between the golf balls, pebbles, and sand with beer to show that there is always room for spending time with friends. The professor explains that the golf balls represent family and health, the pebbles represent possessions and career, and the sand represents unimportant tasks that can overwhelm a person's life if not kept in perspective.