Frederick Herzberg, Work and the Nature of Man (Goodreads)
I found this one via Seth Godin's post about hygiene factors—a sort of baseline attribute that doesn't matter much when it's there, but is quite negative when it's gone. Herzberg writes about it in this book.
Also I'm a sucker for picking up 50 year old books from the library. Completely different smell profile than a new book.
From Chapter 5:
How comfortable it is to be able to earn a living today on yesterday's knowledge, but how often this leads to obsolescence.
It is in the exposure to the unfamiliar that we look for evidence of psychological growth. Is it not legitimate to ask, after a job assignment, whether an employee has learned anything--has he in this case added to what he knows? For success does not necessarily accompany psychological growth, while very often failure gives rise to considerable growth. To be sure, all tasks do not provide much in the way of the unfamiliar, particularly because jobs today are so very much overstructured.