Yes or No

Today, I would like to introduce a funny story on which I read in the paper, regarding a Japanese guy with poor English:

He is a government official who has been appointed as a staff of the United Nations. But, he is not confident at all about his English skills, and he decided to apply a rule: in order to deliver his opinion in the meetings, say simply « Yes » or « No ».
He kept this rule strictly to carry off the difficult discussions, and 3 years passed by: it is time to back to Tokyo.
He was very happy to escape English, but his boss in UN called him to say:
« It is for the first time to meet a Japanese person who express his own opinion very clearly, which is most appreciated in our organization. Now, it would be grateful if you could extend your post 3 years more… »
He smiled at his boss, but his answer was very clear and simple, as usual,
« No. »