Don’t trust a source that never admits what it doesn’t know.

Honest accounts have edges, because anybody who knows a subject well knows where the evidence runs out. A source that answers every question with the same confidence has either stopped checking or is selling you something, and those missing hedges tell you about the method rather than the strength. Certainty is cheap to produce, which is exactly why it is weak evidence of anything.

Look at where you get your information and notice whether anything is ever described as unsettled or revised. Prefer the ones that say what they do not know. When you pass something on, carry the uncertainty with it.