‘A bird,’ I would say, proudly.

‘Barney, it’s a sparrow-hawk. And that one there, bobbing in the water, is a guillemot.’

I followed her finger, conscientiously enough, God knows, but all I could see was some duck.

It was high season. Parties of enrolled students were arriving at Camilla’s school by the hour. Visitors dropped by to ask for prospectuses and while they were at it any other scraps of information to which they felt they were entitled: what time the buses ran, where the castle was (there wasn’t one), whether the harbour was at the top of the hill or the bottom. So Camilla had a double reason for closing her doors and taking me off on whole day excursions. ‘I’m going to show you where you live,’ she used to say, dragging me through the crowds of furious souvenir hunters and thwarted Hardy enthusiasts who were hammering at her windows.

She led me down the sides of sheered off cliffs to lonely rocky beaches where she taught me to tell a gastropod from a bivalve. She introduced me to gribbles. She drove me out onto the mist shrouded moors, where Arthur’s sword was dropped, and made me study bell heather and cloudberry and common gorse. She took me for long hikes into the tinkling valleys and out again on to the perpendicular meadows, where she would set me little tests. ‘I’m going to sit here,’ she would say, ‘and you’re going to pick me a bunch of bluebells.’ And if I returned with anything approximating the size and colour of bluebells – it was enough, initally, that I knew she was referring to flowers and didn’t come back holding up a bunch of worms – Camilla’s eyes would light up with pride, much as if she were the mother of a child afflicted with Down’s syndrome who had just put together his first sentence. I can still see her, in the grass, her lovely strong brown knees drawn up to her chin, her shoulders gone golden in the sun, her face aflame with merriment under the shadow of the black broadbrimmed hat she wore on hot days, and which made her look like one of those tall blonde Spanish women who come from Malaga and own riding schools in men’s imaginations.

As she got to know me better, Camilla evolved a system of encouragements and rewards which might have struck some as unacceptably Pavlovian but which was guaranteed to bring on my rural education by leaps and bounds. ‘If your heart is set on fellatio tonight,’ she said to me – it was, it was; set rigid – ‘you’ll have to collect me some flax, some fleabane, and some fritillary. You’ve got five minutes.’ ‘What’s cunnilingus worth?’ I used to ask, and within seconds I had identified a curlew, a cuttlefish, and was back with armfuls of columbine and bloody cranesbill and lesser celandine.