Memento mori: remember your mortality. You will die one day. What have you done with your life thus far? I don't believe I've accomplished anything that someone else couldn't have done in my place; even my writings and music probably tread familiar ground. Here's an idea; what if the day before you're given a choice, you find out you have one of the more painful genetic illnesses known to man, which debilitates you, but will allow you to live the next 50-100 years in varying amounts of pain?
Also, yes, Superman at his most ridiculous (that's why we call it ridiculous) was definitely capable of solving these issues and furthering the progress of mankind by millenia. Heck, even capable of altering people's minds & bodies to be more agile, logical, insightful, creative, stronger, heartier, and longer-living. Issues of communication, misinformation, control, opportunity, religion, ideology, insanity, violence, famine (the environment in general, really), and disease would be utterly removed by the end of my week, so people could focus on bettering themselves, moving off-planet, and exploring/populating the galaxy at large. (In fact, why stop at advancing just one species of civilized beings?)