"A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects." - Robert A. Heinlein
If one were able to perform all of these things, one would be very diversely skilled and arguably able to handle anything that life threw at them. If one becomes to immersed in only one skill set and then finds oneself in a position where such skills are not needed, but some other skills are, then one is figuratively "up a creek".
Sidetrack: This can also apply to one's thoughts and whether one is able to keep an open mind or if one is too set in their ways.
Back to topic: I think some people who have specialized skills but have found themselves laid off in recent years, and then decided to go back to school for a different (and presumably more marketable) degree or skill set are working towards such an existence, at least more so than someone who has a more narrow skill set that they do not seek to expand upon.
Essentially though, this description is that of a jack-of-all trades.
