Someone left a book

at our front door yesterday.
I don't know who did it and, in a way, I hope I never find out.
You see, it was a library book - one of the books that  has gone missing. I know there are other books as well. 
That library is not my responsibility any more. When it was there were three people from whom I never managed to recover library books. One was in the middle stages of dementia and her husband was unable to find the book. Possibly it had been returned to another library. I told him not to worry. He had other things to worry about. Another joined the group, borrowed the book and never returned it - or herself. I tried to phone her but nobody answered. I wrote to her and the then President tried to call on her. It was all without success. We had to accept the book was lost.
And then there was the member who somehow had multiple books. She had borrowed them in my absence. I changed the borrowing system - something I had wanted to do for a very long time. Someone else went through the previous "borrowing book" and made a list. Oh no, she had returned them. She just hadn't crossed them off.  No, she didn't have that. She hadn't borrowed that one. And no she didn't know where that one was. And so it went on. 
I told her she couldn't borrow any more books. When I had to leave early one day she made a big show of returning a book. After I had gone she borrowed two more. I pounced and told her that she was banned from the library and that I had the support of the then committee. When she moved house we tried to get her to return the books as she packed. They never came back. We haven't seen this year and I left chasing her to the new librarian anyway.
The book which was "returned" to me was not borrowed by her. It was one of the books I passed on to the group when I had written the review.  It is about an interesting style of knitting but not one I would ever do. It's slow and fiddly and I don't much care for the end result.
All that though is not the point. It's a book that now belongs to the group. It should have been borrowed in the normal way and returned in the normal way.
There seems to be something about books that makes some people not treat them in the same way as other things. They wouldn't dream of keeping anything else belonging to another person but a book seems to be different. I am still upset by the loss of books I have loaned - or, more likely, the Senior Cat has loaned - to other people. One of the more recent losses is a book signed by the author.
     "You'll get it back," the Senior Cat told me. It hasn't been returned. The borrower passed it on to someone else - and can't even remember to whom they gave it. 
Right now I have my own library books which I can account for and know when are due and the book left on my doorstep. Barring unforeseen circumstances I will return the former by the due date. I will also return the latter at the first opportunity. 
Yes, somewhere in the past I have forgotten to return books but, like most people, it has never been deliberate. I don't knowingly have anything belonging to someone else - although the mass of ex-library books (bought and paid for) on my shelves might suggest otherwise.
I suppose too that it is better that the book was left on my doorstep rather than not returned at all. I just wish people would return things they borrowed, especially books.