I got bronchitis – absolutely spontaneously – at the age of thirteen.

The night before it was diagnosed I crept down and looked it up in the encyclopedia. There it was, ‘acute bronchitis’, which was what the doctor said I had. Better still, though, was ‘chronic’ bronchitis: you got that at least once a year. I asked old Cyril Miller, our GP, whether there was any chance that I might develop, or acquire, the chronic kind. Praising recent scientific breakthroughs and modern drug techniques, he said this was unlikely. Chronic broncho was reserved for nicotined oldsters with suede-shoe lungs.

Yet, if you want a couple of weeks in bed (as I did, bi-annually), and if you have indolent and credulous parents, it’s amazing what a few packs of French cigarettes will do.