Anne Frank was put into a real awful situation at an extremely horrible time in history, making her learning curve very steep. Sure, her diary is filled with the normal fare of a 14 year old (e.g., disliking peeling peas or thinking about boys), but very often she fills the pages with neat insights, thoughts on the workings of the world, and constructive criticism of her character. One of my favorite passages:
How noble and good everyone could be if, every evening before falling asleep, they were to recall to their minds the events of the whole day and consider exactly what has been good and bad. Then, without realizing it, you try to improve yourself at the start of each new day; of course, you achieve quite a lot in the course of time. Anyone can do this, it costs nothing and is certainly very helpful. Whoever doesn't know it must learn and find by experience that: "A quiet conscience makes one strong!"
This book is good because it was the real life of a young girl who was dealing with a rough situation the best way she could, and all the while trying to become better. How would each of us deal with such a situation? How do each of us deal with what we've got? This book makes you think about it.