I recall reading an accounting of someone meeting a Japanese cabinetmaker or carpenter (or maker of some kind) that they considered to be a hero. The maker was too sick to talk much to whoever was blogging about the encounter, but the spouse of the maker was well versed in what the maker did and what their views were.
The only thing I got from reading the story (which seems to be the only thing the writer got) was that as they were leaving, the spouse of the maker grabbed the person and "begged" them that whatever they do, they should do it in rhythm.
If I get a rare clear four hours of time in the shop (because I have small kids), I recall that comment and try to keep the rhythm going. It does two things: 1) it keeps me from hurrying, which is just a way to end a shop session earlier either being exhausted or from the frustration of a stupid error, 2) it keeps me from standing around just as you said - self congratulating or pondering. A gentle self-reminder gets me back into the flow, and without hurrying.
I get a lot more done and it feels a lot better. When I first read the article, I thought it was kind of dopey, but I get it now.