In the kind of teaching I do with children with special needs, it's often like blowing up a balloon. You work and work to fill it up, and then all of a sudden - POP! - and it explodes with knowledge. That "pop" moment is pretty amazing. I had a student this week who is learning to speak, and he has just made the connection that when he looks at my mouth, he can try to imitate the shape to get better sound production. It was the most incredible moment when he went POP! I'm not sure who was more excited!