Many people have already blogged about this so I'm just going to add my thoughts to theirs.
I was introduced to Harry Potter in junior high by my friend Marianne who told me that the books were amazing and you can't put them down. It sounded like my kind of book as I had previously been into everything that Rohld Dahl wrote and other authors like that so I thought I'd give them a try. At that time the 3rd book was out and people were anxiously awaiting the 4th book, I quickly became one of them as I could not put those first 3 books down. The books are just like plunging your face into a pensieve and watching everything happen. Her details are exact and you can imagine every single thing that is going on. I recently finished the series Fablehaven which is also an AMAZING book but one thing I didn't like was when something big happens in the book you have to read and re-read the sentence a few times because there was no warning and it gets a little confusing. When J. K. Rowling writes you understand everything and even find yourself gasping when it happens. I grew up along with the books and had many dreams where I was with the characters in their world. I use to believe that I couldn't see them because they were under the invisibility cloak but they were there. When the first movie came out I was in heaven because I could finally put a face with the characters. I was even more excited when I realized my initials were the same as Harry Potters (at the time) and the actor who plays Harry Potter shared the same birthday as me. I stayed up all night readying those books, I pre-ordered them, I'd go crazy when each book ended because I couldn't wait for the next installment. When the 7th book came out I spent every minute I could to find out how it ended, it made me a little sad though because that world came to an end but I still had the movies to look forward to. With the end of the final movie there was a huge feeling of sadness because I realized I was done with that world. Oh I'll always be able to re-visit the books and even watch the movies but there isn't anything else to anticipate anymore. It's like a friend moved away and I wont get to see them again. Call me cheesy and maybe I am but I will miss that world.