John Cleese was educated in left-hemisphere modes (science, law) and thought logically and linguistically; he discovered by accident at Cambridge that he could write things that made people laugh, and he realized the creative writing process was fundamentally different from legal reasoning—a shift from linguistic-logical to intuitive-humorous cognition.

The process of writing comedy is fundamentally different from the process of understanding a legal case; comedy requires a kind of thinking that cannot be explained rationally—some jokes are 'so completely silly that it's almost meaningless,' and you simply cannot explain them.

John Cleese's life trajectory changed from purely logical, linguistic thinking (trained in science and law) to intuitive, creative thinking when he discovered he could write comedy, demonstrating that switching toward right-hemisphere modes of operation made him much happier and more creative.

Processes used in writing comedy are completely different from logical processes and involve working with things that are 'so completely silly that it's almost meaningless' and are simply inexplicable through language.