Confusion is the companion to misunderstandings.
Intuitive concepts take less explanation, since they draw on concepts you already understand and pull on existing ideas.
Frustration is when we keep trying, but hit a roadblock. Overarching concepts won't become roadblocks, since they don't get caught on each pebble in the road.
Discouragement happens when we can't do it.
Real-life ties to topics prove that you already understand the "why", and remove the doubt that you can't understand.