The author discusses their experience with various personal knowledge management systems (PKMS), including Obsidian, and their decision to build their own custom solution. They cite concerns about privacy, security, and the longevity of commercial PKMS, as well as the desire for a simple and flexible system. The author describes their custom PKMS, which is built using a platform called Directus and allows for easy note-taking, organization, and synchronization across devices. The system is designed to be secure, private, and future-proof.