On the birthday of the former South African president, here's a look at his inspirational leadership, in his words.
'No' is a complete sentence, but it can take many people decades to learn how to say it.
Each one offers an entertaining storyline, as well as valuable insights into business success.
There is such a thing as being too honest, and the line can be perilously thin.
What does it take to become a master at your craft? Here are some pointers to get you started.