A primary key to a successful career is to maintain a steady cycle of study-learn-work-produce. Continuous self-improvement is a part of that cycle.
Ade Adenekan tells us that self improvement, whether one likes it or not, will never cease to be a major factor that influences the successful life style of any right-thinking person on this side of the great terrestrial divide, no matter the echelon to which he or she belongs, be it lower, middle, or upper in the society. In order not to be left behind in today's economic, social, and political world, no stone should be left unturned for personal achievement. Remarkable laurels are only for those who have created a notable niche that makes them to stand out of the crowd in their community.
To read more of Ade's thoughts on this matter, see http://informationanthology.net/CareerMentor/Self-Improvement.html.