Last Wednesday, I had lunch with a colleague at a sandwich bar across the road from the office. We sat facing each other over a little table and ate soup from limp cardboard cups. I had slung my handbag across the back of my chair and, when we stood up to leave, I found that the bag had left before me. I'd been so consumed by office gossip that I hadn't noticed someone had quietly helped themselves to my beautiful, supple brown leather bag – and to my entire working life that was inside it.

Bother, bollocks, bugger, blast, I thought.

I'd bought the bag a year ago – in that impossibly long ago age when it still seemed a good idea to spend an unconscionable amount of money on a handbag. Inside was a BlackBerry, iPod, ￡200 in cash, a wallet containing a stack of credit cards and passes, a wad of receipts for unclaimed expenses, two notebooks, my diary and my keys.