The average person would have quit at the first failure. That's why there have been many average men and only one Edison.

Thomas Edison once observed that the reason most folks don’t recognize opportunity when it comes knocking is that it is often dressed in overalls and looks like work. Edison knew that anything worthwhile never comes easily; if it were easy, anyone could do it. Because he persisted far beyond the point the average person would consider reasonable and rational, he produced inventions that even the most learned people of the day considered impossible. Great advances in knowledge are often achieved by people with an almost fanatical devotion to finding the solution to a problem. Flashes of inspiration alone are not enough to ensure success; they must be followed by determined, persistent action.