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Why is Cartan's magic formula $\mathscr{L}_X\omega = i_Xd\omega + d(i_X\omega)$

called "magic"?

Should it be considered a highly surprising result? Does it "magically" prove several other theorems? What is the etymology? (Why it is variously referred to as E.Cartan's formula and H.Cartan's formula?)

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    Maybe because $\mathscr{L}_X$ is of $0$-degree (derivation) and is nicely related to a $1$-degree map $d$ and a $-1$-degree map $i_X$2013-02-21

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I would have liked to put this as a comment but I do not have enough points to do it.

I think there is some magic in this formula because it tells us that the Lie derivative $\mathscr{L}_X$ is homotopic to zero with the homotopy $i_X$ going from top-right $\Omega^{p+1}(M)$ to bottom-left $\Omega^p(M)$ diagonally in the following diagram:

$\require{AMScd} \begin{CD} \cdots @>{d}>> \Omega^p(M) @>{d}>> \Omega^{p+1}(M) @>{d}>> \cdots \\ \qquad @V{\mathscr{L}_X}V{0}V @V{\mathscr{L}_X}V{0}V\\ \cdots @>{d}>> \Omega^p(M) @>{d}>> \Omega^{p+1}(M) @>{d}>> \cdots \end{CD}$