What is the criterion to judge a man who is already an adult? When I was a child, I always thought was always thinking that being an adult would be a happy thing. In my understanding at that time, adults could do everything, could know everything like the God. However, when I became a senior high school student, suddenly I realized that adults' worlds are was not as interesting as I previously thoughtso interesting in my view as used to be. Adults have a lot of things to consider, such as housing, careers, mortgages and so on. Thus, now I am always thinking about how to behave like an adult.