I agree with you, sort of.
If–what you mean by knowledge is knowing facts.
I mean, there are ideas, opinions, information–but sometimes a person knows a bit about a subject, but not enough to form an opinion.
It also depends on your sources.
You could read every anti-Catholic book ever written, and the fact would be, that you are a well-read individual, because you read many books.
But your opinion doesn’t mean much if you didn’t spend the same amount of time reading pro-Catholic books, because you only got one side of the story.
And, people do tend to read books that agree with their own point of view.
Not because they are bad or stupid, but because we like to be comfortable and don’t like to be challenged.