> It could be just a personal mental weakness with numbers with me that is not general, but looking at my interlocutors emotional reactions to their own numerical predictions I do feel quite strongly that this is a general human trait.

Your feeling is correct; anchoring is a thing, and good LessWrongers (I hope to be in that category) know this and keep track of where their prior and not just posterior probabilities come from: https://en.wikipedia.org/wiki/Anchoring_effect

Probably don't in practice, but should. That "should" is what puts the "less" into "less wrong".