[bmcfeeley]

That's not how words work.

"I don't know everyone who is Japanese" does not mean every person who exists is Japanese.

[leereeves]

Obviously the sample "everyone I know" is not representative. Really, there's no reason to ever mention it.

But mentioning it suggests it is representative of something, and if it were a representative sample, 0% of the sample has trait X suggests 0% of the population has trait X.