Because of the challenges it helps us find ways and understand or selves
you'll be able to know your weaknesses and strenghts
It is pertinent that self discovery is a greater key to unlocking most successful part of our lives. "the more you know you, the better you become"--- this presumably sum the totality of discovering one's strength, weaknesses, self-challenges and the likes. Apparently, this gives you an edge over what the outside world think of you.
In same vain, familiarity with your personal challenges provide you a wider range of thoughts---as a rational being, you tend to see the big picture easily than when you are ignorant of your self challenges.
Subsequently, your innermost self gains more confident in dealings! You'll have a better knowledge to relate in the public, making decisions, and probably leading a mass of people to a more promising success. Similarly, you know what you can do and can't do; will help you living hypocritically.