Summary of the professional courage book

How was your response to the most famous question, "What do you want to become when you grow up?" Beginning at the age of seven, the answers of most people tend to have jobs such as "famous football player", "teacher" or "a policeman". But after ten to fifteen years have passed, these people find themselves hesitant about this question, most of them change and the answer becomes: "I do not know, I may work with management or accounts and financial!" What happened?