Anne Frank: The Diary of a Young Girl. Well the title is pretty much self-explanatory.
We first meet Anne as a 13 year old girl with a strong sense of self. By the end, she's 15 and wise beyond her years. In the meantime, she is forced to find her way out of that life-sucking-whirlwind that is adolescence while being stuck in hiding (you know the story: Evil Hitler, poor jews, Nazis killing people, etc.) (How's that for an intensive course in history!)
Now, I have a confession to make: I really struggled to get through the first half of the book. It actually felt like the musings of a 13 year-old (duh!) which, to tell you the truth, didn't interest me that much.
On the other hand, the second half of the book read as an entirely different story (fortunately): Anne's psychological maturity peaks (the changes are palpable), her writing style becomes more grounded and structured, her daily reflections sink deeper in the study of the human condition within the walls of her confinement, not to mention the political glimpses that are a constant reminder of the war state outside the Secret Annexe.
All in all: an interesting read when put in perspective.