Erol,
Prior to the collapse of the USSR I used to meet Russians and other people of the Eastern block. Most of them knew English well enough. By the moment you even tried to made a hint or ask a question about their political system they would pretend they forgot all their English, and did not understand what you said.
In the begining I thought maybe they really did not understand`, so I repeated the same things all over again trying to make them understand. The more I was repeating the more they would pretend they did not understand.
No further comments....