What idea challenges me the most

Recently, someone asked me what idea most challenges me. I have to admit that I had to think for quite a while to come up with an answer that truly reflects who I am and what I think. What would you have answered? Not easy, right? I thought about what I really like and what is important to me. Since I was young I wanted to become a doctor. To me, medicine was the one way to allow people who had a car accident or were diagnosed with a disease to live long and happy lives. I thought that medicine could cure every wound and avoid pain and misery to spread. However, as I grew up I realized that the world had too many incurable wounds that all the medicine could never make them go away. I realized that civil wars, misery, pain, poverty and cruelty would always exist. Then we learned at school the atrocities that happened during World War II. But what we were not taught at school is that similar atrocities are still happening everyday in some developing countries in Africa where civil wars are raging. So I suppose the idea that challenges me the most is to become a doctor and work in a refugee camp in a developing and try to avoid as much as I can the wounds to bleed, the pain to paralyze and the misery to spread and, by doing that, I would little by little begin to cure the world.