I agree with John on this one. People have had knowledge about the water cycle for thousands of years but it is only the last 50-100 years that we have the technology to study it in detail and learn more about it.
There’s lots of amazing observations in ancient texts. People back then were just as clever as we are now, it’s only that their technology wasn’t well developed (which made doing science hard) and they hadn’t put their knowledge on a rigorous basis (they didn’t really have any idea about hypothesis testing, or statistics, let alone double-blind trials!). So though some things were correct, perhaps surprisingly so, other stuff was completely off.
A hilarious example of this is Aristotle (who lived 2350 years ago). He offered a carefully argued reason as to why men have more teeth than women, based on them having more blood. But he never thought to check that women do in fact have more teeth than men!
Of course, men and women have exactly the same number.