You mention ‘solve world hunger’, implying you know that’s the outcome already. That’s an easier choice then, isn’t it. The point I’m making is that doing something because it’s the right thing to do regardless of whether you know it’s going to work is what makes it a bigger sacrifice. The person I was replying to was also implying they would only consider sacrificing something if they knew the outcome first. If we all did that we’d never achieve anything.