As for building detailed inferences on generalised or flimsy data,
I’m reminded of the Cairo tour guide who told his clients
“This particular pyramid is 5002 years old.”

When asked how he could pin it down with such accuracy, he explained:
“When I started working here the year before last, I was told it was 5000 years old.”

In other news, I learned a new word today.
Sciolist: Knowing many things but knowing them badly.
Not sure if knowing that that makes me me feel smug or small.