The worker, as a specialized function within the division of labor, is worn down by a sustained exposure to high volumes of distinct work. And similarly, different individuals become more sensitive to different types of wear. The motion and repetition of something often determines the pattern of wear.
In a larger sense, one sees new entrants in the workforce bright-eyed and bushy-tailed as they say, and over time their enthusiasm wanes as they find that their initiatives for transforming their environments are suppressed.
Even a new job after a string of many is perceived as a new beginning, a birth, and the energetic intervals afforded by these bursts of energy shorten further and further as the worker becomes more cynical.
