Some kind readers occasionally suggest that I should be prime minister. I disagree. I recoil from the prospect of breakfast with presidents Vladimir Putin and Nicolas Sarkozy, or feigning patience with cabinet colleagues. I am bad at giving bland answers to unwelcome or stupid questions, or listening to the repetitive bleatings of lobbyists. I am not a natural mediator; preferring to sharpen issues rather than to elide them. I find it difficult to deliver inspirational messages, especially when I have nothing to say.

I suppose that if the Queen were to ask me to form an administration I should feel obliged to say yes, but only after an extended effort to persuade her she had made a mistake. I empathise with Mario Monti and Lucas Papademos, but I do not envy them.

In politics, as in other professions, the people best at it have learned the trade. The fall of Herman Cain, the Republican candidate in the race to contest the 2012 US election, was as predictable as his rise was unexpected. Silvio Berlusconi’s business achievements are remarkable but as premier he has been undistinguished, even by the modest standards of Italian politics. If Michael Bloomberg is the most conspicuous recent exception to the rule that successful politicians are politicians, it is because the job of Mayor of New York City can be done well by someone who treats the role as that of chief executive.