Scientists representing the Soviet Union traveling overseas were enjoined from mentioning certain technical topics that might reflect negatively on soviet socialism, and were required to refer any questions about those polar bears to their accompanying commisar.
Wait, did I say "polar bears"? Sorry. Sorry. Never mind. This comment has nothing to do with polar bears. There is nothing here about polar bears.
The only thing we can be sure of about the future is that it will be absolutely fantastic. So if what I say now seems to you to be very reasonable, then I have failed completely. Only if what I tell you appears absolutely unbelievable, have we any chance of visualizing the future as it really will happen.
- Arthur C. Clarke (h/t Brin)