I’ve always figured that was a huge part of it. The more you learn, truly learn, the more you discover there is to learn.

People who leave getting an education with leaving schooling think they’ve learned all there is to know. They also never get beyond being spoon fed and regurgitating information.

So, they’re “experts". If they’ve heard one idea (one or multiple times) they “know" all these is to know. They also never learn to wrestle with concepts.