It's funny you say that, in high school I knew all the countries of the world and their capitals. I also knew all the major rivers, lakes, and mountain ranges. But that was over 20 years ago and I've forgot most of it. I was ashamed the other day when trying the large countries test the first time and only scored like 70%. I couldn't believe how much I had forgot. But after about 30 minutes I had them back to memory. I may start doing capitals if I stick with it and master the countries first. I still need to work on Africa. I'm about 80% after a half dozen tries.