The truth is that people who study more books are the ones who know more about a particular subject. A person who stidied 1 book for lets say economics knows less than the person who studied 10. If a person is given 1 hour to study a topic and other is given 10 hours. Its most likely that the second person will perform better in the subsequent test than the first one. Everyone is not extraordinary. You are saying that almost everyone who passed css is extraordinary. Anyways l am just telling people about my experience. If they don't want to take lesson from it, its their choice.