10 in binary _is_ 2 in decimal. I think you've made an off-by-one error in your critique.

But it's (decimal) 3 in ternary, I think that's the point (you get a 3rd group of people if you're mistaken about the base)

Could be that I missed the joke.

In fact, 10 in any base represents the base number.

Good point, but not in base 1.

> In the unary system, the number 0 (zero) is represented by the empty string, that is, the absence of a symbol. Numbers 1, 2, 3, 4, 5, 6, ... are represented in unary as 1, 11, 111, 1111, 11111, 111111, ...

https://en.wikipedia.org/wiki/Unary_numeral_system

And those who know that "10" can be any number if you change the base.