In her thought-provoking post What are piano lessons for? she makes these points.
1. Piano lessons are for learning to do cool stuff on the pianoThat's the skellington. Now please check out her whole article.
2. Piano lessons are for learning what the piano can do so you can do whatever you want on it.
3. Piano lessons are for understanding other people better
4. Piano lessons are for understanding yourself better
5. Piano lessons are for understanding the world better
6. Piano lessons are for exercising your body, your emotions and your intellect all at the same time.
7. Piano lessons are for changing who you are
8. Piano lessons are for joy.