Almost all great people, whether bad or good, and especially our heroes fail successfully and succeed humbly. They are very human like each of us. The darks in a painting are as important as the light colors.
Almost all good times are preceded by difficult ones. Well, how can that not be true. What I mean is that often very difficult circumstances reveals heroes who help shape a better future, one that may not have come about otherwise.
William Wilberforce
Roads in life are not straight. William Wilberforce, who sought to end slavery, was defeated again and again politically. The harder he tried the harder failure hurt, but without realizing it he was helping shape a new age.
Eventually at the right time, in place of compromise and gentle progress there came a sudden catastrophic evolution to the slave trade. Many benefiting from and promoting it suddenly lost both wealth and power. A growing social movement combined with this unexpected event made all the difference.
The lesson here, is that failure can be a deceptively short-sighted label, especially when pushing to accomplish some important cause. Wilberforce was ultimately very successful despite dark times of discouragement and failure. He not only limited slavery but changed the whole western world.
Of course this happens to all of us, where failure is normal and continuing is the solution. I think of the movie Lion King, amusingly. We all have set backs and negative moments which are just part of the path to accomplishing life or some purpose.
Thomas Edison
Often success would be a curse, when our attitude or course is wrong. In hind sight, a wrong way of doing something becomes more obvious, but failure can turn us away before then.
Edison was so accomplished and successful in beginning the electric age that he could not accept alternating current over his own ideas.
Ford was quite successful in revolutionizing the car industry, such that he could not see and evolve with a changing market. These cases aided general healthy competition, but not before causing painful personal failure.
Hitler should have failed, except for arrogant national beliefs and allied mistreatment, before ruining his own country. All have now learned how to treat defeated nations.
The Wright brothers began the modern age of flying, but one of them became so consumed in patent wars that they both lost the joy of their accomplishment. What was 'right' or 'wright' could have been graciously given up to allow them to make less but continue innovating. (The truth is they alone could not keep up with the movement they so strongly pushed forward.)
Churchill and Lincoln
Churchill was brought low many times for many mistakes but overcame personal failure and continued his very unique ways. Thus he was uniquely prepared for unlikely times. Success at any point may have disqualified him for his future role as prime minister. In any case, his failures did not.
Lincoln was too small to have much harsh opposition when he jumped to nomination for president. This last idea sounds counter-logical, but while failing so many times, he kept up goodwill with his rivals, who were instrumental in helping him secure the nomination.
Conclusion
The point is, success is not linear. One needs dark colors to appreciate the light when painting. Failure teaches our evolved brain as well as the successes.