Among the jumble of postcards, newspaper clippings, maps and to-do lists that cram the walls around my desk is a school photograph. The occasion was the annual fair at which a group of us had commandeered the brightly coloured parachute used for junior school games. The photograph shows four girls – my friend Tanya, in white prefect’s blazer and sash; two of our younger protégées, all drooping knee socks and jauntily loosened school ties; and a child of 6 or 7 fresh from a visit to the face-painting stall – huddled together on the grass beneath the billowing parachute in the moments before the tent collapsed around our shoulders. I don’t remember the seconds after the shutter snapped (I was the one taking the picture) but the image records a golden period, at once bittersweet, anxious and exhilarating, in the weeks before Tanya and I left school for good.