We know the similar story with Michael Jackson. Even he went through the same kind of life. His father wanted him to succeed at any cost. Even he did not have a normal childhood. I have heard these stories with most of the child prodigies. Close to home, I heard that it was Sridevi's mother who pushed her into acting and dancing. I heard the same story with Hema Malini.
There is one common thread in all these stories. It was the parent's ambition that their son/daughter has to be in a profession. And they made their child go through a rigorous routine which robbed their childhood. In most of the cases they did not even find out if the child is enjoying what he/she is doing. The parent wanted to become something, they could not achieve it so they want to achieve it through their child whether the child is inclined towards it or not.
I was shocked to hear when Agassi said "I hated tennis". I think all these stories give us a biggest lesson in parenting that you should not force your children to fulfil your unfulfilled dreams. Treat them as separate individuals.