The document outlines the 100 Days of Happy challenge which encourages participants to recognize small things that make them happy each day for 100 consecutive days and post about them on social media. The rules are to focus on one's own happiness rather than trying to impress others. Successfully completing the challenge helps people become more optimistic and appreciate the happy moments in their lives. Examples of early happy days include the first day of school, new cheer uniforms, and seeing puppies at a local festival.