There are a couple of reasons for a person’s success or lack of success:
- Luck: success is not necessarily an indicator of skill or foresight, but may be the result of fortuitous circumstances. That is, success may be the result of luck.
- The right skills for the situation: intelligence is not fungible — it is not equally effective in every context. The skills and knowledge that a person has may be perfectly suited to a certain situation at a certain time, but change the situation slightly or shift the time and the skill set may no longer be suitable. (Lesson learned: continually update your knowledge and skills.)
— Extracted from The Wisdom of Crowds by James Suroweicki
[Definition] Fungible: When two or more things are inter-changeable, can be substituted for each other, or are of equal value, they are described as fungible. (Source: http://www.pathtoinvesting.org/dictionary/words_f.htm)