Re - reading books!

I only get books on kindle now (like to read in bed with light out) and luckily Amazon very kindly put a note onscreen "You purchased this book on such-and-such date". Saved one or two re-purchases!

Yes, I have often found myself thinking "this is familiar" a few times when reading a new book. Sometimes I'm not sure until I get near to the end if I have actually read it before or if it's just similar to previous books. These are all fiction books though. My DH is the same, but we are both prolific readers, and mainly read physical books from the library than online.

DH is an avid reader and carries a "little green book" if we are likely to go near a book shop, which is an address book. He lists the books he's read under the author's surname iniitial. Prior to this he has had duplicate purchases.

I used to work in a library, and some of our readers - usually older women - would make their own secret little pencil mark somewhere at the back of the book, to remind them which they'd read!
It applied most often to the type of fiction with very similar covers - e.g. romances, or what a naughty colleague of mine used to call 'She had to take in washing' books, which I have to admit did crack me up when she first said it.

Yes I volunteer in a library and its annoying when people deface books like that Witzend
I have been known to buy the same book twice as the Amazon message doesn't come up for used books. Sometimes authors re-release books under a different title which I think is unfair unless its clearly stated that this is the case.

I've been caught out too. Usually when the book has been reprinted with a different cover.

I have shelves full of books, all of which I have read at least once. I am going through them now reading them again.
If I can't remember what it is about within the first few pages, I can then decide if I want to keep them or remove them. If I can remember it, I want to keep it because I might forget it in the future :-)

I've done the same... the story is familiar and then I remember that yes, I have read it before. But if it is enjoyable then I keep going!
Sometimes a second read gives you a different perspective on a book, or you can take time to enjoy the writing while knowing what the plot will bring.

I wondered what the strange pencil marks on the back pages of library books were for!! I agree they shouldn't be allowed to change the title of the cover without clearly stating this somewhere, I have been caught out and disappointed by this a few times.

I find this a rather strange question. I buy lots of books, some of which I read once and then give to charity shops. Those I thoroughly enjoy, I keep and read again. I have favourites which I read over and over again. When I no longer enjoy them, I give them away.

*RosieLeah" I get my books from libraries like the OP so I don't always remember that I have read a book a few year's ago when I pick it up from the shelf. I read several books a week so it's a lot of books to remember. Not complaining just an observation on life that I can sometimes be halfway through a halfway through before I realize it read it before.

I must admit I'm addicted to books but I don't think I've duplicated - yet. There's still time, though.