What you're saying makes absolutely no sense. Do you even speak another language than English? Millions of people each year have their graduate education on languages other than English and are doing fine. They do learn English for broad communication, but what you're implying is that they couldn't even think in their own language since it's inadequate.

I'm sorry to say but you're full of it if you believe what you wrote. It's an absurdity only someone who has never travelled or been exposed to the world could say.