Am I the only one who thought this was referring to how people felt about the general zeitgeist? Like, how Romans viewed everyone outside Rome as barbarian, etc. Not in the literal sense like, mirrors. Nice HN switcheroo.

Yeah that was my original interpretation of the title too! Perhaps something like:

How did early humans understand their situation and what did they think the 'world' was like, and what did they think they should do with their lives?! I find it fascinating to think how that longing to know what it's all about has changed so much for humans over time.

Mirrors are still heaps interesting though, as is reflection/refraction/light-transport in general I'd say! But it wasn't about what I expected when I read it.

Yeah, I thought it was a more avant-garde question, like Greek philosophical literature.

It turns out the title has a literal meaning."