Not everyone uses Obsidian or Notion. Your knowledge is scattered across email archives, saved PDFs, browser bookmarks, and files sitting on your desktop. Claude reads all of those formats.
Point Claude at a folder of saved articles and PDFs. Ask it to summarize recurring themes, extract action items, or build a reading list from what you've collected. You can also ask it to compare notes across different sources and flag contradictions.
I pointed Claude at saved bookmarks exported from Chrome. It categorized them, flagged dead links, and grouped the rest by topic. That cleanup would have taken me a full afternoon.