Based on the proven principles found in Dr. Stephen R. Covey’s best-selling business book, The 7 Habits of Highly Effective People®, This is a video titled Big Rocks teaches us that when we’re faced with a mountain of work (like building a car) and we need to prioritize, the best way to approach these projects (and your life) is to start with the Big Rocks First. This is covered in Habit 3: Put First Things First. The 6 other habits (for those interested) are:

• Habit 1: Be Proactive
  Responsible for behavior, results and growth.
• Habit 2: Begin With the End in Mind
  Focus time and energy on things that can be controlled.
• Habit 3: Put First Things First
  Execute on most important priorities.
• Habit 4: Think Win-Win
  Work effectively and efficiently with others to achieve optimal results.
• Habit 5: Seek First to Understand, Then to Be Understood
  Communicate effectively at all levels of the organization.
• Habit 6: Synergize
  Innovate and problem solve with those who have a different point of view.
• Habit 7: Sharpen the Saw
  Seek continuous improvement and renewal professionally and personally.

Hope this helps.