One of the most unsettling experiences of my life happened when I was 18, browsing through the shelves of my college library. A book caught my eye and I started to flick through it. Suddenly, halfway through the book, a photograph fell out and floated down to the floor. I picked it up and to my horror, it was of me.
My heart started pounding and I quickly put the book back, making sure that I kept the photo. I went outside and took deep breaths. Only later did I realise that I had borrowed the book a year earlier and used a photo as a bookmark.
I mention this because I have spent today flicking through dozens of secondhand books and found several photos that were used as bookmarks. This one is my favourite:
We're used to seeing individual passport photos of people, but there is something terribly private about a sequence, where we can see the subject trying to strike the right pose, experimenting with different moods. The man above appears both ridiculous and touchingly vulnerable.
This young woman clearly isn't comfortable having her picture taken and is nervously biting her lower lip. Is she still alive today, I wonder?
This bookmark is dated 1959 on the other side. It is only a fragment, but there is enough to see that it is an advert for the Albanian dictator Enver Hoxha's favourite film star, Norman Wisdom.
On this scrap of paper, someone has gone to the effort of copying out the last paragraph of a novel just below the actual text.
Here is the only real bookmark I found all day, imploring the British to use their new National Health Service - TOWARDS A FITTER BRITAIN. I wonder what the founders of the NHS would make of today's obesity epidemic?