Flying is hours and hours of boredom sprinkled with a few seconds of sheer terror.
The air battle is not necessarily won at the time of the battle. The winner may have been determined by the amount of time, energy, thought and training an individual has previously accomplished in an effort to increase his ability as a fighter pilot.
Months of preparation, one of those few opportunities, and the judgment of a split second are what makes some pilot an ace, while others think back on what they could have done.