Bruce Forsyth, national treasure, started compering ITV's Sunday Night at the London Palladium in 1958. His mock-desperate cry of "I'm in charge!" soon became a fixture.
It resonates because everyone in any working environment is familiar with the spectacle of the panic-stricken manager suddenly realising that the whole caboodle is slipping out of control and shedding bits as it goes.
It's easy to see how it happens. The leader allows the team to get on with the job, and then realises, too late, that it's all going wrong. In school it is the head's realisation that one department will wreck the results. Then "I'm in charge!" becomes more of a confession than an assertion of authority.
The trick is to balance letting people do their thing while ensuring they know the boundaries. The clear "I'm in charge" statement has to come at the beginning of any enterprise, not when things are fraying at the edges, but how does it chime with the notion that you need to listen, hang back and provide space?
One of the best demonstrations was by Louis V. Gerstner Jr, who rescued IBM from near bankruptcy. In his account (Who Says Elephants Can't Dance Harper Collins) he recalls a lecture by the manager of one IBM business, illustrated with OHP transparencies or "foils".
"Nick was on his second foil when I stepped to the table and, as politely as I could in front of his team, switched off the projector. After a long moment of awkward silence, I simply said, 'Let's just talk about your business'."
Nothing could have said more clearly both, "I'm in charge!" and, "I'm ready to listen to you."
Gerstner, clearly, was the leader, not the manager of detail. "I manage by principle, not procedure," he said. "Solve problems laterally," he told his managers. "Don't keep bringing them up the line."
Can we distil some points for school leaders? Doing the "I'm in charge" thing early on is obvious. The equivalent in school might be dropping a regular meeting that often has nothing to talk about, or getting the word "Head" erased from a parking space: actions where the symbolism is more important than the message.
The instruction to "solve problems laterally" is worth thinking about, too. I once tried to involve a senior education officer in a difficult decision and he was having none of it, saying, in an entirely friendly way, "Tackle it, Gerald. Then let me know."
It's a phrase I recommend. Use it soon. Look your worried colleague in the eye and say, "Tackle it. Then let me know."