It’s spectrums all the way down.
There’s an old nerd joke that goes, “There are 10 kinds of people in this world —those who understand binary and those who don’t.” The joke is that in binary math (that is, base two), you count using only one and zero, so 1 is 1, 10 is two, 11 is three, 100 is four, 101 is five, and so on.
There’s a slightly newer nerd joke that goes, “There are ten kinds of people in the world, those who understand binary, those who don’t — and those who understand ternary.” Ternary is base three, which counts like this: 1 is 1, 2 is two, 10 is three, 11 is four, 12 is five, 20 is six, and so on.
You could continue this joke ad infinitum, simply by referring to a handy list of numeral prefixes: “Those who understand binary, those who understand ternary, those who don’t, and those who understand quaternary” (base four) or “quinary” (base five) or senary (base six), etc etc etc.
The thing I like about this joke is that it challenges your assumptions about categorization, reminding you that there’s no way to really know how many buckets things might be sorted into.
