1.You get to revisit somewhere you know and love. What's better than the security of knowing you will like a book? You have that when you reread. I find comfort in knowing what's going to happen and knowing that my favourite characters are going to be safe and sound (or not).
2.You have to opportunity to think more about the book without focusing so much on a new story. You might realise things that you didn't otherwise because now you already know what's happening because you don't have to use all the focus that comes with reading a new book.
3.You remember things you forgot. I've read and reread the Harry Potter books a ridiculous amount of times and yet there's still little details that catch me because I'd simply forgotten and it's always really interesting things that you can't believe you forgot.
4.It's interesting to see how your thoughts on it vary from the first time you read. You might see things in a different light now or you might disagree with things. If you're a blogger this could be exceptionally fun because why not make a post about the changes in thoughts or the new thoughts you've had on a book. It's even fun as a non blogger. I recently reread a book I loved when I was about 12, thinking I'd still love it and I thought it was utter crap but it was so cool because I used to love it with all my heart.
5.Reviewing. This one particularly to myself because I only recently began reviewing so now I have so many unreviewed books that I know need to review. I could have so many more reviews just by rereading books and reviewing them. It get's me so excited just to think of all the reviews and organised thoughts.
6.It's just genuinely nice to revisit things. This kind of falls into my first reason but I want to reinforce it. It's kind of like visiting an old friend. You get to remember the characters and all the fun things they did (and the not so fun). It's just a genuinely nice experience.
You've probably noticed that I really love rereading. It's just so nice and refreshing. I don't think books are meant to be read once and then cast aside. Why not love them over and over and over again. Share them with friends, let them experience, let them love. I simply love visiting all the characters who hold a place in my heart.