How about this one... A new student joins, lets say she's an adult woman. She comes to classes, and does not wish to have contact. She shys away from being hit. You can tell it, and she even closes her eyes sometimes.
Her stances are very bad, the shoulders are not square. The Instructor tells her this, and it still will not correct.
BUT --> and here's the good part... She persists in coming to class, and gets stronger, learns the ways of the school. She tests and gets a higher belt.
One day, you see that she has been endowed with a sort of aggressive mindset --> she now gives and takes in sparring. Her kiya is more mature. You can see that she is learning, and that this school has changed her!
I myself have seen this kind of thing a few times (the student may be a child, or an adult, male or female, doesn't matter --> I just think that in my own personal experience I've seen it most with adult female students).
This, to me, is just simply an amazing thing to witness. Sometimes I think that it takes a whole school full of people to grow a good martial arts student -- I suppose that's why private lessons seem like such a strange way to train to me.