[zchrykng]

... I'm not sure what part of "If you extend that logic to the world" you didn't understand.

[neutronicus]

The logic is inherently local.

The typical student does not emigrate or even travel that much, so you don't prepare them to encounter a human randomly selected from the population of the Earth, you prepare them to encounter a human randomly selected from the regions where they are likely to spend their lives.