Its long but its worth the read.

Basically, he had a disease that his brain would forget how to speak. People with this can sometimes sing or talk loudly. It worked with him for some words. Oh, and nobody has ever recovered. He found that he could talk in rhyme, like Jack be nimble, Jack be quick, Jack jumped over a candlestick. So he kept practicing that and remapping his brain. Now he can talk better, in rhyme.

Just read it.