I just recently learned this term. Apparently, in a brilliant burst of zeitgeist-savvy, Stephen Colbert coined (or reactivated anyway) the word truthiness to describe that it-just-feels-right! certainty we all know... when, in fact, we have no actual, you know, facts. Or proof. Or, possibly, logic or sanity.
But we're absolutely sure we're right anyway.
I stumbled across the word six years later (early adopter? me?) used in an article to describe factoids that seem to prove what, in fact, they do not - because shorn of their context, perhaps, or incomplete. Facts which are accurate, as far as they go, but turn out to be deeply misleading and misused to buttress ideas that feel truthy...
What a perfect word! So much of life today is truthy.