This reminds me of an excerpt from an old Emacs manual:

    . . . if you forget which commands deal with windows, just type @b[ESC-?]@t[window]@b[ESC].

I think the better advice for command-line editing would be to set up the mouse.

I have yet to see a shell that has mouse enabled line editing support. It should certainly be possible though.

I do prefer vi bindings at the same time though. Vi bindings and mouse support complement each other well, you don't have to choose one or the other, just use whichever feels most natural and convenient in that exact moment.

> This weird command is presented with such a benevolent innocence as if it's the simplest thing in the world.

I think it's a question of context and familiarity. To a vim user, like me and, I assume, ahmedfromtunis, their examples do indeed seem simple and natural. Presumably, to an emacs user, the example you quote (if it's quoted literally—I don't use emacs and can't even tell) is just as natural, and assuming some comfort with emacs is presumably OK in a manual for the software!