The chairman of Barclays, Sir David Walker, was in an earlier life the chief executive of the Securities and Investments Board, the forerunner of the Financial Services Authority (FSA).
So there is certain symmetry to the reports which surfaced this week that Hector Sants, until recently the FSA chief executive, may be heading for a senior role in the bank.
People talk of gamekeepers turning poacher and vice versa, but in fact the border between the private sector and public service barely exists any more.
John Tiner, who was Mr Sants' predecessor has just signed off as chief executive of Resolution, the insurance group, though he seems more enthusiastic about a micro-brewery in Devon he and his family run on the side.
His erstwhile chairman at the FSA, Sir Callum McCarthy, now chairs Castle Trust, a new kind of housing-finance provider. He also has an office at Promontory, where the global vice chairman is Michael Foot who was in charge when bank regulation was moved from the Bank of England to the FSA after 1997.
It is the same in Government. Cabinet Secretary Sir Jeremy Heywood left Downing Street for a four-year spell at Morgan Stanley, the investment bank, before heading back across town.
It makes a lot of sense for those who regulate to have some idea what life is like in the real world – particularly when so many of our politicians have never had a proper job outside.