Ultimately, even her amazing talent could not keep up with her ego. She was no longer merely trying to do her best mentally — she was trying to be the greatest of all time.
If you are just doing your best you expect to have off days and make mistakes. When you are the greatest of all time, you can’t make a mistake and every failure gets magnified and becomes an obstacle that can’t be overcome. Her ego subjected herself to a standard no one can ever meet and she snapped.
No doubt about it - she finally snapped under all the pressure.