Over your life you evolve. You physically grow up. You emotionally develop. You psychologically change. This all occurs through your experiences in life and through interaction with other people. You cannot fully evolve without facing challenges. In this way, challenges are gifts for your growth. The more you face, the more capable you become, the more expertise you have, the stronger you are, the more tools you have in your inner toolkit, the deeper the wisdom you have to draw upon. Challenges add to the depth of your character and allow you to draw upon this in future situations.