That's true of pretty much any knowledge you don't gather first-hand, though. It's not a binary thing, it's a spectrum. I don't have any first-hand knowledge t

That's true of pretty much any knowledge you don't gather first-hand, though. It's not a binary thing, it's a spectrum. I don't have any first-hand knowledge that black holes exist, but there's a great deal of evidence that pushes me into the "95% sure they exist" column. Similarly if multiple people tell me someone is an asshole, that pushes my needle on the spectrum to "66% sure this person is an asshole." You can, and should, maintain skepticism about any conclusions you draw. But that doesn't mean you can't draw conclusions at all until you verify the information yourself and are 99% sure of something.