Geographic literacy
I was thinking recently about the famous question of what places Americans can find on a map, so I decided to take a blank map and test myself with no preparation to see how many countries I could label on the map. (How do other people do? You could try to use Inkscape to write labels on the blank vector map.) I was hoping to get over 100, given that there are just about 200 countries in the international system.
Unfortunately, upon completion of the exercise, I fell short by just a single country, getting 99 countries right. I also fell short by a single CPLP member -- São Tomé e Principe -- so I could have reached 100 if only I had remembered all of the CPLP members.
I did particularly well in Europe and South America, achieving nearly perfect coverage of each continent. Apart from the Caribbean and Pacific island nations (many of which don't even appear on this vector map and almost all of which I would have known if they had been present), my weakest spots were:
Central America
Central Asia, especially the former Soviet republics
Former Yugoslavia (I remembered all the countries and their orientation to one another, but I was off by one when I started to label them)
Southeast Asia (I transposed Thailand with Burma and Laos with Cambodia)
Africa (I transposed several West African and North African countries that I thought I knew, and only thought I knew the location of 22 African countries to begin with)
