A couple of years ago a national newspaper was giving away free books. It wasn't my newspaper of choice but, you know – free books. So I would always have a glance in the newsagent to see what the current offer was. One week it was Shirley Jackson's We Have Always Lived in the Castle.

Now, I absolutely adore this book, but I didn't bother picking up the newspaper that day. I have, you see, already got a copy – there's a picture of it above. You might think that, given the rather sad state of it, I would jump at the chance of a clean, fresh, free copy. But that never occurred to me. My old 1960s paperback might be battered, bruised and beaten, but it is truly beloved.

I'm not sure how long I've had that Shirley Jackson book. Ten years at least; probably 15. Maybe more. I've read it perhaps half a dozen times. And each time I take it from the shelf, another sheaf of pages has come loose. The glue in the binding has deteriorated some more. The spine is scuffed and ripped, the cover is fading by degrees. But I could no more consider getting rid of it than I could put a bullet in the head of a geriatric dog.

The book doesn't have any particular emotional ties – it wasn't given to me by a loved one, nor found in any special place. I didn't read it for the first time one unforgettable night. But – for reasons that seem unclear and perhaps a bit odd now I come to examine them – I just wouldn't get rid of it, or replace it with a new copy.

Perhaps it's because my books have travelled with me all my life, their numbers swelling, becoming a much more unwieldy herd whenever I've had to move house. They've been lent out, brought back; their spines have been cracked and their pages spread-eagled on tables and floors; they've been rubbed with suntan lotion and their corners turned down; they've fallen in the bath and been left in the garden all night.

Perhaps it's because they mutely accept such abuse with the faithful, unconditional stoicism of our imaginary geriatric dog that I don't part with them. They've toiled hard for me, in difficult circumstances, and like some benevolent squire of old I feel it's my duty to provide a comfortable place for them in their twilight years.

I looked on the internet for the average life of a paperback book while writing this. Some people said 10 years, others longer. There are guides available which tell you how to look after books; one I found on eBay, aimed at bibliophiles, says: "Take the book from the shelf, avoiding too much dragging. Place the book gently on its spine and on a flat surface. Using a hand on each side, allow the book to open somewhere near the middle. Most books will do this naturally. Turn to the place you want by turning sections of the book over. Never press down on the pages near the joint or force the boards back beyond the flat position."

Where's the fun in that? Books shouldn't be wilfully mistreated, but we shouldn't handle them with kid gloves. If they pick up imperfections and blemishes, then so what? A less than pristine book is a book with character. As we might, in time, come to look like our geriatric dog, so our books come to share with us the scars and scratches of life.

That's one of the reasons why I'm in no rush to start digitising my collection on a soulless ebook reader. Ripped, torn, stained with tears and coffee and beer, falling apart, I love all my battered books, and I bet some of you do, too. Share your falling-apart favourites here and on our Flickr stream.