When I was about six (so about 1978) my mother made a television film for a current affairs programme about the high levels of lead in the water in Edinburgh, where we lived - the lead poisoning was causing a degree of brain damage in some children. She wanted to show a child having a blood test, and the simplest thing in terms of consent etc was to use me. I was nearly as excited as the time when my godmother asked me to be her bridesmaid, but as on that occasion, I didn't show it. And I tried not to show it when the needle went in, so it can't have been a very exciting three seconds of television. But of course for ME ... My mother brought back the old-fashioned reel of film on which my pale blue school jumper appeared in miniature a hundred times - I hope it might still be about somewhere. I wouldn't have mentioned this moment of screen glory if it weren't for the fact that my oldest friend, Joshua - now impresario of this magical bus - was also then a six-year old living in Edinburgh, and drinking the same poisoned water. So we two and the boy who sucked on the car have a special bond. It turned out that my lead levels were quite high, which I have found something of a consolation, over the years.