I was introduced to the book First Things First in graduate school and loved it. I loved hearing and reading the story about the rocks. It is important to put the big rocks in the container first and then all the smaller pebbles and the water will fit in between the big rocks.
This is a metaphor for life. If we put in the big rocks of life: God, family, job; then all the smaller pebbles of life will fit in between the crevices. For any projects we have, in order to complete each project, we must be able to insert the big things (the big rocks) first, then all the other smaller things (the pebbles and the water) will fit in.
In memory of Stephen Covey’s recent death at the age of 79, click on this video for an explanation of the big rocks: