I disagree. In my opinion, if you can't explain something to someone else, you don't really understand it. But that doesn't make the article wrong. While you d

I disagree. In my opinion, if you can't explain something to someone else, you don't really understand it. But that doesn't make the article wrong. While you don't understand something until it seems obvious to you, it does not imply that you understand everything that seems obvious to you.