I suppose "stupid" questions are all a matter of perspective and depend on the general knowledge of the individual, and their knowledge of professions and world affairs outside their own "world".
I frequently travel from Australia to Asia and on a recent flight to Indonesia the F/A serving my meal commented that they had seen me a number of times on flights they were on headed to Malaysia and Indonesia, and then asked if my frequent trips were for business or pleasure. I replied that they were business trips.
The F/A then asked what sort of work I did and whether I was based in Australia or overseas. I replied that I was based in Australia and that I was a consultant working on World Bank projects.
The F/A then asked where in Australia were the World Bank branches situated as they had never seen one, and then asked if it was the overseas division of one of Australia's major banks.
I must admit I was more than a little amazed as I was flying on QF, not a third world airline.