I think you're looking at it wrong.
I think more what he is getting at is that grown ups are plagued with ideas and beliefs that interpret the world around them. He's getting at an idea, the highest point of human intelligence is observation without evaluation.
If you interpret things in a stupid way, they'll sound stupid. If the meaning isn't clear, try and search. Someday you'll realize that the conclusions you draw from those sorts of statements say more about you and your ability to thing and gain insight than the author of the statement.