> I've always defined my level of expertise in an area in relation to how easily I can explain it to someone who knows absolutely nothing about it. That's righ

> I've always defined my level of expertise in an area in relation to how easily I can explain it to someone who knows absolutely nothing about it. That's right. As my teacher used to say - if a professor cannot explain the essence of his work to an elementary school student, he doesn't understand what he's doing.