This first working week of January is apparently the time when we’re most likely to think about a change of career; and last Friday was the 30th anniversary of the launch of the FTSE100 index of leading companies listed on the London Stock Exchange. The combination of those two diary items made me wonder what choice I would make if the job genie swooshed out of the pantomime lamp and told me I could re-invent myself as chief executive of a FTSE100 company.