In my professional career I was very concerned with the problem of the competing interests of doctors and others who had received rather too much 'hospitality' from drug companies. With the inevitable result — over prescribing, and inappropriate over emphasis on expensive drugs rather than others. But here there are no commercial interests, no payment has been made to anyone, no lavish dinners have been eaten, no sponsorship has been asked for or received — and there is no advertising (apart from my own book). How can this be? Because writing it is pure fun, and I am lucky enough to be on a final salary pension. Remember those?