I had lunch with an accountant today (and I bought him lunch, even if it was only a Costa sandwich). We were talking about what architects need to know when they were setting up their own practices. Although he was obviously well informed and canny, his prime piece of advice was a statement of the absolutely obvious. 'You have to invoice,' he said, 'and if they don't pay by the due date you have to chase the invoice. Don't just imagine they will pay it.' This advice evidently came from his experience of dealing with architects who don't do that. We have all, I think, been foolish financially in different ways, in our personal or working lives. Those statements of the obvious are really useful, and show the intelligence of the person who remembers to make them.