I'm a well-educated and fairly intelligent person, but once in awhile, an awareness or a thought suddenly hits me that makes me feel very dense (maybe I've spent too much time in the African Bush?). Yesterday, I was running those endless errands, working on my pre-African departure checklist, when suddenly I decided I'd better grab a quick lunch.  I stopped at a local fast food place, something I seldom do, and placed my order at the counter. The girl told me my bill, but then I noticed she...