What do you infer from Darwin's comment on his indifference to literature as he advanced in years?

Darwin, a great scientist, known for his work On the Origin of Species, enjoyed literature only until he was 30, as he said. He enjoyed poetic works of Byron, Coleridge, Shelley, etc. immensely. Shakespeare's historical plays gave him much pleasure. However, as he advanced in his age to reach the benchmark of 30, the charm faded and he began losing interest in pictures and music that once gave him great delight. He tried reading poetry and Shakespeare; however, he found it so intolerably dull that it nauseated him. It is surprising that the answer to this change is in Darwin's own statement. His mind had become some kind of a  grinding machine to process laws out of facts. It caused atrophy of that part of the brain on which higher tastes depended. It was hard for Darwin to infer it as well and, thus, his romance with literature died away.