As Fry says, the limit to someone's understanding is never their ability to understand. The limit is always in their motivation to care. And she sees her role as being to provide that motivation.

"I think what you need to do," she says about the key to connecting with a wide audience, "is to create a hole in people’s imagination. If I can create just a moment where you want to know the next bit – you know exactly the size and shape it needs to be to fulfill your craving for that exact piece of information – then everybody's in."

I wish we had more teachers that thought like this.