This drama taught me many lessons and in my opinion showed the real life of a human being. Every human being is the main role of his book. Many people say that destiny has already been written and we can not change it. This is exactly what the characters experienced on stage. People who were not aware of themselves lived a life without choice and interest. But the people who tried to change it had choices life of their own at the end. At the end of the series, we saw that the world of secret was destroyed and people entered a new world. And it taught me that there is another world and there was. The hardships that Yoo Joo Da was going through were in fact hardships that are written in the destiny of every human being, but they can be fought only when you are aware. We saw that "jinmichae" in his previous life, he hurriedly killed his mistress. But in the life of the book of secrets, he lived his life with patience and in the end, he stayed happily with his beloved .... I learned many other lessons that I do not remember at the moment. This series was really great and opened my eyes to the human world