To play Devil's advocate, why is it useful to spend time learning about these types of things -- world politics, economics, even current scientific developments? Is it mainly because it's interesting (so that it's primarily entertainment)? Or is it to better yourself in some way? I think a lot of people implicitly think that this type of knowledge falls into the "bettering yourself" category, but I wonder if it's mostly for entertainment. Of course, if you are actively involved in international politics, then things look different, but I'm mainly talking about the "everyperson".
I bring this up because I go through phases where I get really into world "happenings" as described above, but then after a while I feel as though I have gained little or nothing, except emotional responses and opinions about these things, which causes no noticeable positive effect in my day-to-day life (and in fact, often affects my mental state negatively, given the amount of fear-mongering in media). Instead, I have the suspicion that all of that time would have been better spent focusing on things local: myself, friendships, family, hobbies.