Dr. Jekyll and Mr. Hyde

Japanese elementary schools will start to teach English in the third grade in 2020, two years sooner than currently. And I am concerned about something. In a TV commercial aired by one of the most famous cram schools for colleges, the English teacher explains the grammatical difference between "at the ceiling" and "on the ceiling." Understanding this difference is important to pass college examinations. But don't you think that Japanese people have many other things to do before understanding such a difference?

We, Japanese, love to speak English. Everyone does. But our feeling to avoid being embarrassed by mistakes is much stronger than the curiosity to learn English. This is partly because in Japan being talkative is deemed to be self-centered and stupid. (This is why we like the proverb "silence is golden.") Also, we don't want to be treated like babies because of our English proficiency level.

Generally, the more fluently a Japanese person speak English, the less Japanese their attitude is. This is most hated by those who only speak Japanese. English speaking Japanese often abandon or are ashamed of their local culture. Even when speaking in Japanese, they think and speak as non-Japanese do and those who speak only Japanese see through it and feel that they are excluded.  

So, why don't we become "Dr. Jekyll and Mr. Hyde," i.e., behave according to the Japanese protocol (e.g., polite, quiet, shy) when communicating with Japanese speakers, while, when talking with non-Japanese speakers, act according to the global standard (e.g., smiling, assertive, eloquent)? It is needless to say of course that we have to have the third personality to control these two personalities.  

I don't want to replace my local culture with another, but want to accommodate more than one culture and keep and grow them both.