Powerless over people, etc....
The part of the quote you refer to refers to the fact that as a recovering alcoholic I have to accept that my biggest adversary is ,'self will', referred to in the,'Big Book' see p.60, ,'How it works' 4th Ed. as, being like the director of a stage show, always wanting everything to be perfect, the lights, the set, the actors costumes and lights etc., etc., of course it never is just quite right, but I've got to run the show.
In recovery then it relates to the firsttwo of the12 suggested Steps, more specifically to Step 2, ,'Came to believe that a Power....etc., then to Step 3,' Made a decision ,...etc.
So when I say ,'I am powereless...etc., I am reinforcing the fact that I am no longer ,'running the show', I have handed my life and will over to the god of my understanding, eradicating ,'self will' and with whom I'm never, in a spiritual sense alone, albeit I may be in practical terms, I mean ley's fave it you can be alone just about anywhere.
Anyway, your question helped to remind me of a few things, for which I thank you, Mike W.