This book is divided into two "casual writings" and "essays." "Casual writings" are more unique, written in a very free style and without any form of default constraints so the author can put down the most authentic expression of random feelings. The author is not trying to "write a paper", lack of audience awareness and does not attempt to draw "conclusions". So this book is purely "private writing" ,very sincere and friendly,just like the author is muttering to himself. The fact that such a "narcissistic" approach has won so many readers makes the author feel very surprised.