It's only odd because I don't do this. I don't have anything against re-reading but I have so much un-read stuff and so much more on my to-be-read list that re-reading isn't an option. There are plenty of books I'd like to re-read for enjoyment or further understanding but not until I run out of new possibilities.
I once started reading a book by John Green, that I later put down, and years later started reading it again only to catch myself about fifty pages in (I put it down the second time as well). So… The Cavalier in the Yellow Doublet by Arturo Perez-Reverte I'd read and enjoyed; it's one that I didn't leave comments for. It's book four in a series and while the plot of each is different the author is so hellbent, in a good way, in communicating Spain to the reader that it was a bit difficult to immediately figure out that I'd already read this book.
So I should just put it down, right? Read something else that I haven't read before, right? Well I can't do that because I'm one-hundred pages in and while some of it feels familiar; some of it still feels fresh and new and I'm completely hooked as if it were the first time I read the book.
So yeah… I'm re-reading a book; first time that has happened in a very long time.