‘The whole of my life I’ve had difficulty.’ I heard Sylvia say this through the door, which was slightly ajar. ‘Sometimes it’s absolute torture.’ I knocked and entered my mother’s small sitting room unctuously, bearing a tray on which were two gold-rimmed Royal Worcester cups and saucers, the cups filled with steaming, freshly poured Yorkshire tea. On a reclining armchair, with her legs stuck out, and she herself thickly covered in a colourful variety of thin and thick blankets, my mother was listening to the monologue, or perhaps soliloquy, being delivered by the woman in the reclining chair opposite, also with her legs stuck out. My mother was keeling hard over to port, perhaps under the weight of the blankets, and although she looked close to death again, she was politely trying to look keenly interested in what her visitor was banging on about.

‘Last week, gosh, it was so bad I went to see Dr Popinjay about it and he referred me to the constipation clinic. Constipation clinic! I had no idea such things existed! And do you know what? They were absolutely marvellous. Why, thank you, Jeremy. Most kind. On there’ll be fine. What’s that on your head?’

Another unforeseen complication had arisen with my online varifocals order. Now they wanted me to send a photograph of my face with my debit card stuck to the forehead, just above the eyebrows. From this they could accurately measure the distance between my pupils, they said. I had restrained my fringe with a tight elastic band and my Nat West debit card was fastened to my forehead with a small square of double-sided carpet foam tape. I had been photographing myself upstairs when I heard a visitor arrive and hastened down to make tea, which is one of my duties.

‘It’s the Mark of the Beast,’ I said. ‘As prophesied in the Book of Revelation. In the end times, Satan will pour out his spirit into the world, and we will be forced to bear his stamp. It’s now mandatory. Haven’t you heard?’ Anxious for a moment, she looked to my mother’s ashen, inexpressive face for guidance and saw that she was on her own. Given my past form, however, I was probably playing the fool. ‘Go on with you,’ she said. Her mind made up, she curtly dismissed such nonsense from it and went gaily on with her most recent success story.

‘I’ve been sitting all wrong they told me. Did you know there is a right way and a wrong way? I had no idea. And do you know what the best position is?’ Greatly interested in the right and wrong way, the tea boy had lingered. ‘Forehead resting lightly on the splash carpet?’ I said. ‘No,’ she said, entering now into the teasing spirit of a party game. We looked to my mother in case she felt like joining in and hazarding a guess. But simulating keen interest in what was being said had taken her to the limit of her powers. So it was my turn again. ‘Hands behind the head, fingers interlocked?’ ‘No,’ said Sylvia, childishly pleased to have confounded us, my mother and I former nurses and all.

‘Elbows on knees,’ she said, a conjuror whipping away the white handkerchief and enunciating each word separately. ‘And as you strain, you have to say a magic word. And I bet you can’t guess what that is.’

‘Open sesame?’ I said. ‘No.’ Think sheep, Jeremy. You must say “Baa” and open your mouth very wide as you say it.’

Even my mother stared in disbelief at this. ‘Baa?’ she said feebly. ‘Baa?’ I said, incredulous. ‘Baa,’ said Sylvia, demonstrating the correct mouth, which should be open to its utmost limit. ‘Baa,’ said my mother, even at this late stage willing to learn. ‘Baa,’ I said, practising for tomorrow morning. ‘Baa,’ said Sylvia, giving us the model enunciation once again in case we’d missed a crucial nuance the first time.

And then Sylvia went on to extol the surprising magnificence and efficiency and kindness etcetera of the NHS, as wealthy people do who go private mostly but don’t mind occasionally roughing it for something interesting or surprising to say at supper parties.

‘And do you know what?’ said Sylvia. ‘I can’t tell you how effective it is. It works an absolute treat. I’m was so grateful I rang up the clinic to thank them and tell them that my life has been transformed.’ ‘Baa,’ said my mother, trying to fix the word in her mind before it vanished for ever and without trace. The tea boy remained sceptical, however. The word, or sound, sounded unnecessarily specific. Because occasionally I’ve found that ‘Get out, you bastard’ works equally as well. But I kept this criticism to myself.