Yeah it’s so dramatic, and since you can feel it grow colder and darker in the minutes leading up to it, I imagine that it must have been quite unsettling.

Actually, around 150 BCE, this would not have been a surprise. Humans first started noticing a pattern around 600-400 BCE, with around 200-100 BCE being able to predict them to some degree, although it was around 200 CE that we started getting much better, with significant refinements in accuracy around 800-1200 CE, 1715 CE and 1825 CE.

But it would not have likely been a shock in 100 BCE