The document discusses the iceberg phenomenon as an analogy for human beings. Only 10% of an iceberg is visible above water, while 90% is below the surface and invisible. This represents how for humans, only a small portion of who they are - their knowledge, skills, and behaviors - are visible to others, while a much larger portion consisting of their attitudes, values, motives, beliefs, and ethics remain unknown. Maintaining a positive attitude is emphasized as being one of the most important factors that determines a person's success and happiness. Several quotes on developing and sustaining a positive attitude are provided.