Fascinating to hear. I am trying to cut alcohol - still not entirely successful.
But I've been able to cut for months at a time. Whenever the cut happens, I feel my brain sort of "return" roughly a week or two in.
I'm not sure how to explain it other than something like fog clearing. Obviously makes some intuitive sense when you read it.
However, as someone that has consumed alcohol somewhat regularly (sometimes more, sometimes less) since college, it's bizarre to think about that consumption in retrospect. In effect, years and years of "fog" - it makes me wonder how different or similar life would have been without that fog.
Can't change the past now, but a data point and strong signal for the future.
I feel that same way you described with the "fog" clearing. I don't know exactly what it is, but I'm imagining it being the fact I _finally_ get some good, restful sleep (with it taking about 2 weeks give or take for that clear headed feeling to regenerate).