Cancer has turned me into an old dog in a vivisection laboratory. I let the oncologists do what they feel they must, and then curl up in a dark corner waiting for them to do it again.

Writing keeps me sane because it helps me to forget. Kindly editors send me books to review, and The White Umbrella, my first children’s book, saved my sanity when I was being roasted by radiotherapy.

Animals make me happy. I have always loved dogs. Their deaths, when at my command, have been by far the most painful decisions I have made and from the anguish of not one of them have I ever recovered.

Work has always been with paintings. My mother made looking at them fun, tutors at the Courtauld Institute taught me to understand them. Christie’s taught me connoisseurship, and experience taught me to make judgments.

My need for sex has always been as frequent as my need for coffee: so urgent, random and thrilling that love has played little part in it. I suppose it has been an addiction.

Slow travel has been a constant delight: drifting around Europe at 40mph, from museum to cathedral, palazzo to château to schloss. Walking in the wake of Alexander across Turkey; walking in Cappadocia; walking in Armenia.

Nothing scares me more than the prospect of Ed Miliband or Nigel Farage as prime minister. Cameron has been a disgrace, but he is the best of bad choices.

If I could change one law, it would be the one that permits halal slaughter, if such exists. I’ve seen it done and it ain’t pretty.

I would like to reduce the human population of the world to one 10th of its present figure. The globe might then recover from the scars we have inflicted on it. If we restrict our breeding, we might have another Eden. I fear, otherwise, we are destined for perdition before the end of the century.

Cars have been a constant passion. One of my deepest regrets is my failure to buy a car made in 1931, the year of my birth, for my 80th birthday. Still, it was the worst of years for cars, in the midst of the Great Depression. A V12 Packard of 1932 should have suited me. A Riley Nine would have been more sensible.

It may be ending wretchedly, but mine has been a most enjoyable and instructive life. From extreme poverty as a child, to the Second World War in London, to the subsequent austerity and sheer blossoming of life in the 1950s.

I am afraid of dying, but not afraid of death. Looking at my suddenly emaciated body, scrawny and cadaverous, the pain, degradation and the inability to die with any dignity seem inevitable. For more than a year death has been imminent; it is too cruelly slow a process.

As a National Service soldier I learned how to kill. So I can – I am certain – kill myself, if I realise soon enough that I must.

The White Umbrella by Brian Sewell is published by Quartet Books at £9.99. To order a copy for £7.99, go to bookshop.theguardian.com

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