The last book

 I really enjoyed this last book of Harry Potter and it was one of the best from the series in my opinion. What sort of bothers me not only in the last book but also in some of the other books is the behaviors of the Slytherins...When the battle of Hogwarts was about to commense the Slytherins all chose to run away and desert the castle. I mean what kind of loyalty is that...?! The castle and staff all protected the Slytherins for years and years but they give nothing in return. It's hard for me to believe in the fact that Griffindor and Slytherin used to be friends and shared views. As for Dumbledore's past, I was actually pretty surprised. All throughout the series there was this stereotype that Dumbledore was this holy person who was perfect in everything. However in the last book we're exposed to Dumbledore's true identy and see the mistakes that he made which was pretty fascinating.