We take other people’s knowledge and opinions upon trust
Something worth reflecting upon:
We take other men's knowledge and opinions upon trust; which is an idle and superficial learning. We must make them our own. We are just like a man who, needing fire, went to a neighbor’s house to fetch it, and finding a very good one there, sat down to warm himself without remembering to carry any back home. What good does it do us to have our belly full of meat if it is not digested, if it is not transformed into us, if it does not nourish and support us?
— Montaigne in The Complete Essays (“Of Pedantry”).
It's easy to take others' opinions and make them our own. This isn't hard.
We don't need to read the whole report, just the executive summary. Who has time for the nuanced argument? Do the thinking for us. We only have time for conclusions please.
It's easy to skim a book to get to the point as we see it. “We skip reading the whole thing,” Seth Godin writes, “because it's easier to jump to what we assume the writer meant.”
It's easy to gloss over the parts that contradict our opinion.
We read but often we don't digest. Reading involves effort; the more you put in the more you get out.
The same applies to conversations. We are so busy thinking that we understand the other person that we start thinking about what we want to say before they've even made their point. We're not listening.
When it comes to taking the opinions of others and making them our own, we skip the thinking. We don't do the required work.
Complement with how to retain more of what you read.