The speaker discusses the development of a 'Mind OS' project aimed at creating an operating system for the mind to enhance cognitive functions. Stuck in defining belief systems for this project in 2022, the speaker turned to Zettelkasten for information collection, eventually leading to writing a book on personal knowledge management. The book emerged as a diversion from the original project, with the realization that the amount of information to be learned exceeded the capacity of the mind, prompting the speaker to leverage Zettelkasten for organizing and sharing knowledge.