Epilepsy and other seizure disorders have also been associated with higher levels of creativity. It would be reasonable to consider that this could have been at the root of at least part of his talents. Sadly if I recall correctly his mom left when he was around the same age that he told her that he wasn't sick anymore. A child might think that's their illness is the reason for a parents departure. He may have been trying to get his mom to stay by telling her that he wouldn't be sick anymore. I don't discount faith , but I just don't think his seizures would have gone away completely. They may have gotten milder to nearly non existent as time went on, or he may have hid that they were still occuring. I had a patient who had seizures that were left untreated due to severe neglect as a child. She suffered brain damage as a result of a fall during one of the seizures as a toddler. Her cognitive function was basically that of a six year old child ,but chronologically she was in her 50s. Despite this she could do amazing drawings and could play piano like you wouldn't believe. It's interesting how the brain can rewire itself.