Although time always passes on at a fixed speed, we all feel that its speed has been gaining year by year. Why are we under such an illusion？The answer was once given by Qian Zhongshu who thought that happy－go－lucky people deem that time’s speed has been accelerated. This point of view is consistent with that of Einstein who said sitting with a pretty girl for two hours seems to be one minute when explaining to young students his theory of relativity. I think a busy life can also make the dedicated forget the time has worn on. What’s your opinion？