The big rocks signify the really important things in your life, such as health family and friends. The pebbles are the other things that matter in your life, such as work or school. And the sand signifies the remaining small stuff, such as material possessions.

The rocks represent your greatest priorities. The pebbles represent important priorities. The sand represents minor priorities. And the water represents everything else. When prioritizing what matters to you, you must put the rocks in the jar first. They will not fit later. And so it is with the pebbles, sand, and water.

The rocks represent the most important things that have real value – your health, your family, your partner. Those things that if everything else (the pebbles and the sand) was lost and only they remained, your life would still have meaning. The pebbles represent the things in your life that matter, but that you could live without.