When the Soviet Union collapsed in 1991, the communications trade union for which I then worked received several delegations from the emergent nations and we ran courses for them on how market economies operated and how free collective bargaining was conducted. As is my practice when lecturing to foreign audiences, I had my visual aids translated into the vernacular, so I used overhead slides in Russian, although of course I spoke in English and had an interpreter.
I cannot read the cyrillic alphabet and know very little Russian, so I just worked through my slides in order. However, there came a point when I could tell from the statistical data on the latest slide that, for the previous ten minutes, I had been speaking to the wrong slide. British students would have pointed this out in seconds, but none of the Russians had said a word.
I was perplexed and asked why nobody had told me that I had been speaking to the wrong slide. Eventually one brave soul volunteered an answer and the interpreter translated: “In our country, no one challenges the teacher”.