You didn’t know about those either. You were taught it by someone else, who learned about it from someone else, and so on. Sure some people discovered things along the way but you specifically don’t get credit for their progress. Does that make you ignorant? What about all the things that those people did discover or invent - surely you can see how the progress they made at that time, with so few resources and advancements, was truly revolutionary. Some of those advancements were far harder and significant than the stuff we like to point at in modern times like rockets.

Credit? Screw credit, that's not what I'm talking about. By accident, good ideas wander into our minds and make us smart. OK, there's some amount of positive feedback in this process (ideas about how to accumulate more good ideas). But "ignorance" means being uninformed, that is, not lucky enough to be inhabited by many of these good ideas in the first place. And there's a lot more of them floating around in modern times, and so it's harder to be ignorant, and easier to be lucky, and well-informed, and since ideas help with being a smarty-pants, it's easier to stumble into being smart. Thus ancient people were stupid, in a manner of speaking.

While they may not have known many things we know today, they had a better grasp of masonry, pottery, and metallurgy than most people today. Likewise, these are people who understood human experience quite well, and understood the animals and plants around them better than most of us today.

Regarding sanitation, there is evidence that they understood the corruption of the flesh and many Bronze Age cultures had topical treatments that were quite effective antiseptics. So, while not understanding what bacteria are, they still knew the effect.

Some modern ideas are about thinking.

And many of those ideas are quite old. People have been dealing with their own minds for quite some time, and the past had far fewer distractions from facing one’s self. Things like mindfulness, CBT, theory of mind, and most philosophy are built upon quite ancient traditions, observations, and beliefs.

Some modern ideas about thinking are modern.

How about: ancient people had brains that were physically similar to anyone modern, and sometimes they came up with one or two good ideas, but they were generally poorly informed and full of misconceptions by modern standards.

I’d quibble about the tone with “one or two good ideas” but with the general meaning, I wouldn’t disagree.

You don't speak Cantonese.

How can you possibly call yourself an intelligent person if you cannot speak Cantonese?

Well, Cantonese is a bad idea anyway.

(I don't like tonal languages because they interfere with tone of voice, and Cantonese has extra tones.)

Being able to read Chinese could be advantageous, and then I'd be less of an idiot, it's true.

I also prefer languages that are comfortable with being disliked.

Huh? Knowledge/education and intelligence aren’t equivalent. Is English your first language? Seems a very basic error to make otherwise.

That's fine, I was just confirming that that was what you meant by intelligence.

It's somewhat different from "smart", isn't it? Since it includes everyone.