A lot of books tend to be like that, how the author remembers a lot of things in such minute detail.
I finished reading it about a week ago. The book is an incredible read, but it's not the best autobiography I've ever read. It is definitely worth a read as the way she pulls through at the end when everyone has given up on her is astounding. I do reccomend it, but also try reading David Pelzer's book "A Child called It", and his brother Richard's side of the story, (reccomended by my friend), "A Brother's Journey."