Two stupids that were said by a friend I was with in Africa:
First stupid: We were visiting a witchdoctor who I have known for many years and who recently divorced one of his four wives. As I was explaining to my friend that the guy now has three wives and he used to have four, a duck waddled past. I told my friend he had turned his wife into a duck. We both chuckled and I thought nothing more of it until the next day when my friend took me to one side and asked me in all seriousness if that really was his wife.
Second stupid: We were heading to the home of a blind man. A car drove past and I waved at the driver who was the sole occupant of the vehicle and he in turn waved back. My friend then asked me if that was the guy we were visiting.