Programming is a serious logical business that requires concentration and precision. In this discipline, concentration is highly related to confidence.

In simple illustration, consider a child who knows how to play a perfect game of tic-tac-toe but does not know that he knows. If you ask him to play for something important, like a candy bar, he will say to himself, “I hope I can win.” And sometimes he will win, and sometimes not. The only reason he does not always win is that he drops his concentration. He does not realize this fact because he regards winning as a chance event. Consider how different the situation is when the child knows that he knows how to play a perfect game of tic-tac-toe. Now he does not say, “I hope I can win”; he says instead, “I know I can win; it’s up to me!” And he recognizes the necessity for concentration in order to insure that he wins.

In programming as in tic-tac-toe, it is characteristic that concentration goes hand-in-hand with justified confidence in one’s own ability. It is not enough simply to know how to write programs correctly. The programmer must know that he knows how to write programs correctly, and then supply the concentration to match.