Most of the brain's work is done while the brain's owner is ostensibly thinking about something else, so sometimes you have to deliberately find something else to think and talk about.

Meaning: Another worker can often find something to improve in work already considered finished. The second barber’s remaining task suggests that completion depends on standards and perspective, without proving that earlier work was careless or endless correction is necessary.

Meaning: People working in the same trade may compete or disagree despite their shared occupation. The proverb highlights rivalry among peers, without establishing that cooperation is rare or that professional differences are personal hostility.