... theory is good for you because studying it expands your mind... Specific technical knowledge, though useful today, becomes outdated in just a few years. Consider instead the abilities to think, to express yourself clearly and precisely, to solve problems, and to know when you haven’t solved a problem. These abilities have lasting value. Studying theory trains you in these areas.

Someone may have all the technical knowledge, scientific intellect and business know-how but when he/she decides to choose laziness, excuses, procrastination, complaining and other bad attitudes, his/her relevance is meaningless.

Material and technical changes are mostly quite visible. But less visible are the changes in the mind of the people, their way of thinking, their conception of the world and the quality of their fears. ("Horizon and Vision" )

Technical expertise is only a tiny portion of what it takes to be a successful employee and, particularly, a successful leader.