My kingdom for a bookmark!

Something strange happened recently. I mean very strange. I was looking for a bookmark to put on a book I intend to start (duh!), while my other bookmarks are already in use. Yes, I read many books at the same time. But I could not find a single bookmark available. All my favourite ones were already in use, and the many, many I got from bookshops (the local one and others) were, well, nowhere to be found. As if they had just vanished. So I was I knew of socks disappearing, but not that. In the end, I found an old, worned out one between two books, so my problem was sold, but the mystery remains. Where have all the bookmarks gone?