This is one the most powerful messages in AA literature.  One that our ability to think, create, and solve problems intellectually is not an asset in our strugle to become sober.  And secondly, for alot of us including this alcoholic, it's an obstacle to our recovery.  Thinking absolutely gets in the way of getting sober.
I was far too smart (I thought) for this simple program and reasoned that I was not as sick as most (which turned out to be true, I was sickER) and didn't need to work as hard (like in school, btw I never graduated, HS  135 IQ down the drain I thought.) and spent the majority of my useful time daydreaming about my psuedo reality (who I thought I was, who you thought I was, and where I thought my life was going).  Fortunately I slipped up one day and told my very wise first sponsor that I had trouble reading because I would slip into day dreaming.  He immediately told me that day dreaming was "self indulgent".   Of course, like several other behaviors that I was involed in (like womanizing) I didn't know what that term meant so I asked him.  He laughed and said "we call it mental masturbation".  Wasting perfectly good time. that could be used to be doing things for your recovery while tittilating yourself (kinda like spending too time on the internets lol).   It boiled down to exactly what i heard many times in meeting.  "You can not think your way to feeling better, you must act (walk the talk) your way into feeling better."   "Working" the program is not sitting around thinking about it."   Making a list of things to do is a good use of time, but must immediately get up and start doing them, otherwise it's just vain attempt of the mind trying to control what's going on on the outside.

I've been blessed with a career in construction.  One the most blessed aspects of this trade is that on bigger projects, you can not plan everything in advance.
There are problems to be solved during the process and the answers will not avail themselves until you get to that junction of the project.  Perfectionism will immobolize you if you think that you can "have it all planned out".   So I tell my guys, when I see them standing around thinking (for too long) about how to
solve problems that they are not yet faced with that. "You can't build this thing in your mind, you have to get in there and wrestle with it for awhile and more will be revealed.  It's possible that you may have to take a couple steps backwards, but progress is often like that.  Two steps forward and one step back, ebb and flow.  If you don't get moving, you're not going anywhere".